Most people prefer to share their documents in the PDF format since it is more accessible on almost every platform and operating system. In some instances, however, you may find that PDF won't open on your computer. If you do not know how to fix the 'PDF won't open' issue, you may end up getting frustrated.
How to repair Adobe Reader/Acrobat. If you've updated to the latest version of Adobe Reader/Acrobat and it hasn't fixed the problem, you'll need to repair your Adobe installation. Close Acrobat/Reader and all open web browser windows. Select the Start button at the bottom left of your screen. Type Control Panel, then press Enter. To do that, right-click the Start menu and select Task Manager. Then, click More Details to expand the default Task Manager view. Switch to the Processes tab, select each Acrobat Reader DC-related. In the application manager, find the entry for Adobe Acrobat. Right-click the app and select ' Uninstall '. To remove Acrobat on a Mac, use the Acrobat Uninstaller in the /Applications/Adobe Acrobat folder.
In this article, we have all the solutions you can use when you can't open PDF. Before we show you the solutions, let's see some of the reasons your PDF won't open.
Related Read: How to Open PDF in a Word Document?
WhyPDF Won't Open on Your Computer
The Reasons Why you Can't open PDF documents on your computer:
- 1. You are using an outdated PDF Reader.
- 2. If you can't open PDF via Adobe Reader, the file you are trying to open could be a non-Adobe document – while it could be a PDF, it could have been created using a different third-party application whose format is not supported by Adobe Reader.
- 3. The PDF file is damaged or corrupted.
- 4. Some of the PDF Reader application files are corrupt.
- 5. The PDF Reader is installed improperly.
- 6. The PDF file is not recognizable – Your computer uses the .pdf extension to know that the document is a PDF and to determine the application to use in order to open it. If your document was sent via the email, the .pdf extension could have been stripped away. This will make the document unrecognizable.
What to Do when PDF Won't Open?
1. EnsureYou Have a PDF Reader on Your Computer
In some cases, your PDF documents will not openbecause you have not installed an ideal PDF reader on your computer. If a PDFreader is lacking on your computer, the only ideal solution to 'can't open PDF'issue is to install a reader. The steps below should help you implement thissolution:
Step 1:Visit https://get.adobe.com/reader/ and download Adobe Reader(this is one of the best PDF Readers).
Step 2: Once you download the installer,simply click on it and then follow the onscreen instructions to complete theinstallation process.
Step 3: After installing the program, test tosee whether your PDF opening issue is gone. To do this, locate a PDF file,right-click on it > choose Open With… > Select Adobe Reader. Yourdocument should open. If it does not open, move on to the next solution.
Note
2. AssociatePDF Files with Adobe Reader
You could be dealing with the PDF won't openissue because Adobe Acrobat Reader is not your default PDF viewer. Byassociating the files which have the .pdf extension with Adobe Reader, you maybe able to get rid of the PDF not opening issue.
On Windows10
Step 1:Click the Windows Start button and then choose Settings.
Step 2:On the Settings Window, select Apps.
Step 3:Under Apps and Features, choose Default Apps on the left-hand column.
Step 4:Scroll down to 'Choose default apps by file type'.
Adobe Acrobat Won't Open On Mac
Step 5:Locate the PDF file type and then hit the '+ Choose a default' option whichshould be available to the right.
Step 6:After hitting the plus icon (+), select Adobe Reader as the default PDF viewer.
Is google chrome freeware. On macOS
Step 1:Locate a PDF file on your Mac and select it. Control-click the file to open themenu and then select Get Info.
Step 2:From the 'Open with:' section, select the Adobe Reader as the default PDFviewer.
Step 3:Hit the Change All button and then click Continue on the subsequent dialog box.
3. Replacethe nppdf32.dll File if You Can't Open PDF in Firefox
If it is impossible for you to open a PDF file inthe Firefox browser, replacing the nppdf32.dll extension should help youeliminate your issue. The following steps should show you how to do this:
Step 1:Close Firefox.
Step 2:Go to c:program filesmozilla firefoxplugins and delete nppdf32.dll.
Step 3:Visit c:program filesAdobeReader 8.0ReaderBrowser and search for 'nppdf.'. Copy it to the folder whereyou deleted nppdf32.dll. Try to openyour PDF file again in Firefox.
4. How toFix PDF Won't Open After Updating Your Windows Operating System
In some instances, updating your operatingsystem, say, from Windows 7 to 8 or 10, could make it impossible for you toopen your PDF files. If you are facing this problem, the steps we have outlinedbelow should come in handy:
Step 1:Press the Start button and then search for 'Adobe Reader'. Once Adobe Readerappears, click its icon to launch it.
Step 2:Once the application opens, hit the Edit button on the left corner of the page.
Step 3:Scroll down on the page that appears and then choose Preferences.
Step 4:Tap Security Enhances. Locate Sandbox protection and then click (uncheck) thechecked box next to 'protected mode at startup'.
Step 5:Save the changes. This should get rid of your issue.
5. RepairAdobe Acrobat Reader or Acrobat DC
In some instances, you can't open PDF because theresources that Acrobat Reader or Acrobat DC depend on are corrupted or damaged.You can try repairing the resources and then try to open the PDF documentagain. The steps below will help you with the repair process:
Step 1:Open Adobe Acrobat Reader or DC. Select Help > Repair Installation.
Step 2:Wait until the repair process is complete and then try to open the PDF fileagain.
6. Consider Adding a .PDF Extension to Your File
If a PDF file does not have the .pdf extension,your operating system won't know that it is a Portable Document Format file.The Operating System won't even know which program is supposed to open thefile. As noted earlier on, files sent via the email may lack the extension.
The most ideal way to open a PDF file that doesnot have the .PDF extension is to add the extension. The steps below shouldhelp you add the extension to your document on Windows:
Step 1:Locate the file whose extension is missing.
Step 2:Right-click on the file and then choose Rename.
Step 3:Add the .pdf extension and then hit Enter on your keyboard.
Step 4:Next, try opening the file again.
7. Try to Fix the File If It is Corrupt
If none of the solutions we have outlined abovehave worked for you, there is a chance that the PDF file is corrupted. The mostideal way to get a corrupted PDF file to open is to first fix it. You caneither use desktop programs or online programs to fix a corrupt PDF file. Bothonline and desktop programs have their benefits and limitations.
Online programs are ideal for documents whichdon't contain any private information. This is because once you upload thedocument to a third-party server, you won't have the ability to control who canor cannot open the file. On the plus side, online programs are usually free.
Desktop programs should help you protect yourprivacy. However, the problem is that most of the programs require you topurchase a license.
By simply doing a simple search on a searchengine like Google, you should be able to find both online and desktop toolsfor repairing PDF files. Below, we will show you how to repair a PDF file usingan online tool known as ilovepdf.com:
Step 1:Visit https://www.ilovepdf.com/repair-pdf
Step 2: Upload the document you would like torepair – you can drag and drop the file or tap the Select PDF file button. Youcan also upload the file from Google Drive and Dropbox.
Step 3: The tool will attempt to repair yourPDF file. Once the repair process is complete, you can go ahead and downloadthe document and try to open it again.
Summary
Ifyou can't open PDF on your computer, this article has solutions you can use toget the PDF documents to open. As noted at the beginning of this article, thereare different reasons why PDF files may not open on a computer. Sincepinpointing which reason is behind the 'PDF won't open' issue may not be possible,you should try all the solutions we have outlined above.
Administrators typically configure installers before deployment so that all users have identical settings. Many deployments simply involve using the Wizard and other basic configurations described in Pre-deployment configuration (Basic). More complex installations may require manually massaging plist files on a template machine.
Since manipulation of client settings through the user interface is not scalable, Adobe provides two key resources to help you configure Acrobat and Reader prior to deployment:
Customization Wizard: A free utility for configuring the installer prior to deployment.
Preference Reference: A dictionary of registry and plist preferences.
Preference fundamentals¶
Before continuing, you should know that:
DC product preferences are located under the track ID 'DC' (for Continuous) or '2015|2017|2020' (for Classic).
The Continuous track uses versionless preferences. That is, over time new preferences will always reside under 'DC' regardless of how many updates are applied.
Naming conventions and paths are relatively similar on Macintosh, Windows, Unix, and Linux systems.
The Preference Reference describes 500+ settings.
There are two types of settings which reside in different locations: a per-user setting and a global setting which require administrative privileges to change.
Feature lockdown is available on Macintosh beginning with 11.0. Lockable features are controlled via machine level settings so the end users can't change them without administrator privileges.
Preference names are case sensitive.
Just because you don't see the preference doesn't mean it doesn't exist:
Some preferences exist internally and are not visually apparent in the registry until after a feature is used. Subdirectories may also appear as the code is exercised.
Many features are not enabled by default and their related preferences must be manually created.
Many preferences cannot be set thought the UI and must be manually created.
The easiest way to configure the product is to exercise the UI and then manually massage the preferences which don't have a corresponding UI.
Plist file details¶
It's always good to remember the following:
Plist files are binary files. Different editors display plist contents in different ways such as XML, structured text, etc.
Different editors may handle preference values in odd ways. For example, the 3rd party Preference Setter application will set
Integer0,BooleanFalse
, butNumber0,BooleanNo
may not work. In XCode, the latter works fine.Plist files are cached during the current session. If you find your recently set preferences are disappearing, note that Acrobat reads the cached copy rather than the edited files and that it then writes out the plist file on exit, thereby overwriting your edits. To sync the cached plist copy with the newly edited plist, type the following in your terminal:
User plist locations¶
Preferences may be configured per user or per machine (by an administrator). Manage preferences by modifying Users/name>/Library/Preferences/com.adobe.name>.plist
.
Plist syntax¶
Syntax varies by plist parser type. Your plist viewer may display an XML representation:
Or something like this:
>> ] /Services [ /c << /EnableEchoSignDetection [ /b false] >> ] >>
When using this format, verify there are spaces between >> and ]. The ending should be `` ] >> ] >> ] >>`` not ]>>]>>]>>
.
Windows vs. Mac¶
The structure, hierarchy, and naming conventions on Mac are similar to that used in the Windows registry. Thus, a Windows preference looks like:
On Mac, an XML representation looks like:
Data types¶
When adding new preferences the key name and data type must be correct. Every preference has a data type as indicated by the integer field under the key. These need to be added in the format that the application can recognize.
For example, to force a digest comparison with EnforceSecureChannel
:
Open
~root/com.adobe.(productname)_(productversion).plist
.Navigate to
[SecurityPubSec]
.Under
PubSec
, add a new keyEnforceSecureChannel
.Create an array element with an integer element specifying the data type and the boolean value.
Integer | Data Type | Description |
---|---|---|
0 | boolean | true or false |
1 | int | An integer |
2 | atom | The string may be UTF-8 and can therefore include Unicode. The field typically contains text. For example, a value for |
3 | number | Double |
4 | text | The string may be UTF-8 and can include Unicode. The Value Data field is entered as text. For example, a value for |
5 | string | ASCII only |
6 | data | A binary blob |
7 | Unused | |
8 | dict | Containers that hold additional keys. |
Controlling updates¶
Disabling updates¶
Disable and lock the Updater settings by setting bUpdater
to false. Doing so overrides UpdateMode
.
Disabling the Updater
Note the following:
DC Continuous track web and desktop updates are released in tandem to ensure cloud and desktop features remain synchronized and compatible. Failure to update desktop components while leaving services enabled may lead to an unsupported configuration.
Updater preferences in the UI support 'Auto' and 'Off' options. The Continuous track of Reader does not provide any UI options and the default is 'Auto'.
Removing the Updater.acroplugin¶
To disable the application's ability to update altogether, use a post install script to move, rename, or delete the Updater.acroplugin file from /Contents/Built-in/Plug-ins/Updater.acroplugin
.
Adobe Acrobat Files Won't Open
Locking preferences¶
Lockable plist locations¶
Note
Do not modify the feature lockdown file that ships with the product at ShowPackageContents/content/MacOS/Preference/featurelockdown
. The application merges the file Adobe provides with your file at runtime.
Locking support on Mac is identical to the support on Windows. Admin preferences can be set in root>/Library/Preferences/com.adobe.(Acrobat.Pro|Reader).plist
. Within this file the path to a specific lockable preference is identical to Windows.
Many preferences may be locked so that end users cannot change them via the product's user interface. Some preferences only reside in the lockdown location and do not have a counterpart in the user preference area. For details about specific preferences, refer to the Preference Reference.
To lock preferences:
Go to
root>/Library/Preferences
Create a new plist file. Preferences for all versions are stored under a version hive. Thus, the
<11>
and any future hives reside in the same file. DC products preferences reside under the track name:/Library/Preferences/com.adobe.Reader.plist(Insidehive'DC')
/Library/Preferences/com.adobe.Reader.plist(Insidehive'2015|2017|2020')
/Library/Preferences/com.adobe.Acrobat.Pro.plist(Insidehive'DC')
/Library/Preferences/com.adobe.Acrobat.Pro.plist(Insidehive'2015|2017|2020')
The feature lockdown file is a system-level plist file in for a root account. The permissions of the plist file should be –755.
Set the version value in the key. For DC, this is either
DC
for the Continuous track or2015|2017|2020
for the Classic track.Add entries as shown in the examples. Note the following:
Always prepend the data type to the preference name (use the same name as on Windows).
7zip download for mac. Verify the path contains the correct product version.
Save and close the plist.
Note
When using the Mac Wizard, keep in mind it creates an identical file in /Library/Preferences/
. If a plist already exists on a client machine at that location, it is replaced at deployment time.
Future product updates won't affect this file.
Locking attachment settings¶
Attachment settings are locked differently than other settings as follows:
Settings exist in a FeatureLockDown cabinet file by default. It is not a plist file.
The file is located at
/Library/ApplicationSupport/Adobe/Acrobat/DC|2015|2017|2020/Preferences/
.This implementation originated with DC product versions.
Do not use Hungarian notation.
If you edit the file, future updates won't overwrite your custom settings.
To modify the file, simply open and edit as needed.
Field | Description |
---|---|
<< | Begin XML element |
>> | Close XML element |
<< >> | Container of the element components |
Entry name designator | |
[ | Open bracket |
] | Closed bracket |
[] | Container for an entry name value |
c | Mac data type |
i | Mac data type |
t | Mac data type |
b | Mac data type |
: | Separates value names from value integers |
Delimits multiple value names in a list | |
( | Begins a list |
) | Ends a list |
( ) | A list container |
Example: Blacklisting JS API app.alert¶
The example below selectively blacklists the JavaScript API App.alert for all PDFs.