Are you experiencing An internal error occurred message when launching Adobe Acrobat? Some users have also reported to be receiving this error when opening a PDF document. Many have reported that when they click on a PDF file in File Explorer, the preview is not shown, and this error pops up. It can occur with password-protected as well as normal PDF documents.

An internal error occurred – Adobe Acrobat error

If you receive the An internal error occurred error when importing a document in Adobe Acrobat Reader on your Windows PC, follow the below solutions to fix the error:

1. Run Acrobat Reader as an administrator.
2. Use the Open With feature to open a PDF in Acrobat.
3. Turn off protected mode at startup.
4. Check if the Adobe folder has the necessary permissions.
5. Repair Acrobat Reader.
6. Uninstall and reinstall Acrobat Reader.

1] Run Acrobat Reader as an administrator

The first thing you can do to fix this error is to launch Adobe Acrobat with administrator rights.

Right-click the Adobe Acrobat desktop shortcut and choose the Run as administrator option from the context menu. You can now try opening a PDF and see if the error is fixed.

If yes, you can make Acrobat always run with administrator rights always using the below steps:

• First, use Win+E to open File Explorer and navigate to the Acrobat installation folder. It is likely to be installed at one of the following locations:
  • C:\Program File\Adobe Reader
  • C:\Program Files (x86)\Adobe Reader
• Now, navigate to the location where the main executable file is present. By default, you can find it here: C:\Program Files\Adobe\Acrobat DC\Acrobat
• After that, right-click on the Acrobat.exe file and choose the Properties option.
• Next, move to the Compatibility tab and tick the Run this program as an administrator checkbox.
• Then, press the Apply > OK button to save changes.

See: Cannot edit PDF files on Acrobat Reader DC.

2] Use the Open With feature to open a PDF in Acrobat

Some users have reported that the error was fixed after re-associating the PDF document to open with Adobe Acrobat Reader. Hence, you can try doing the same and see if the error is fixed. Here are the steps to do that:

• First, open File Explorer using Win+E and navigate to the PDF file with which you are facing this error.
• Now, right-click on the PDF document file.
• From the context menu, go to the Open with option and then select the Choose another app option.
• Next, from the list of apps that can open PDFs, select the Adobe Acrobat app and press the Always button. If it is not listed, browse and select its main executable file from the C:\Program File\Adobe Reader or C:\Program Files (x86)\Adobe Reader folder.
• Check if the error is now fixed.

Read: Fix Adobe Reader error 109 when opening, reading, or saving PDF.

3] Turn off protected mode at startup

Acrobat’s protected mode is a handy feature that is enabled by default. It prevents malicious PDF files from opening arbitrary executable files, modifying system directories, or tweaking the Registry. However, this mode can cause some issues and errors due to conflicts. So, you can disable the protected mode in Acrobat and then see if you can open a PDF. Once the error is resolved, you can re-enable the protected mode for security purposes.

Here are the steps to disable the protected mode at startup in Adobe Acrobat:

• First, launch the Acrobat Reader app.
• From the top menu bar, go to the Menu option and choose the Preferences option.
• After that, move to the Security (Enhanced) tab present on the left-side pane.
• Now, deselect the Enable Protected mode at startup box present under the Sandbox Protections option,
• Once done, click on the OK button to save changes.
• Finally, reboot Acrobat Reader and check if you are able to open a PDF without this error message.

Related: Adobe Acrobat Reader could not open PDF files in Windows.

4] Check if the Adobe folder has the necessary permissions

If your user account doesn’t have the necessary permissions to access the Adobe folder. Hence, provide the permissions to the Adobe folder using the below steps:

First, open the Run command box using Win+R and enter %appdata% in its Open field.

In the opened File Explorer window, right-click on the Adobe folder. If the folder is not visible, click on the View > Show > Hidden items option.

After that, choose the Properties option from the context menu.

Now, go to the Security tab and click on the Advanced button.

Next, click on the Change button present next to the Owner option. Then, click on the Advanced button and hit the Find Now button. From the list of appeared user accounts, select your user account.

Or, you can enter your user account name and press the Check Names button.

Finally, you can press the OK button to save changes. You can try accessing the problematic PDF files and check if the error is fixed.

Read: Adobe Acrobat Out of Memory error in Windows.

5] Repair Acrobat Reader

If the above solutions don’t work, consider repairing the Adobe Reader app. It will fix any corruption associated with the app that might be causing this error. Here are the steps to do that:

• First, open the Settings app using Win+I.
• Now, move to the Apps tab and choose the Installed apps option.
• Next, select the three-dot menu button present next to the Adobe Acrobat app.
• After that, click on the Modify option.
• Then, select the Repair option and press the Next button.
• Finally, click on the Update button to start the process.

Once done, restart your PC and see.

Read: Fix AcroCEF/RdrCEF.exe Application or Bad Image Errors.

6] Uninstall and reinstall Acrobat Reader

If you still receive the same error, uninstall Acrobat and reinstall it. This should fix the error for you if everything else fails. Here’s how to do that:

First, open Settings and go to Apps > Installed apps section. Now, click on the three-dot menu button associated with Acrobat and select the Uninstall option. Follow the prompted instructions and complete the app removal process.

Restart your PC and then download the latest version of Acrobat from its website. Install the program and see if the error is now fixed.

How do I fix A running instance of Acrobat has caused an error?

If you get the “A running instance of Acrobat has caused an error” message, close the Acrobat app and make sure there is no instance running in the background. You can do that using Windows Task Manager. Once done, restart the Acrobat Reader app and check if the error is resolved. If that doesn’t help, you can update Acrobat or repair the app to fix the error. In case the error remains the same, the last resort is to uninstall and reinstall the Acrobat app.

What is the internal service error in Adobe?

“Internal server error” in Adobe is usually caused when your account is blocked. You can try contacting contributor relations via email explaining the error and issue you are facing with your account. You can also try signing in with a different account and check if it helps.

Read next: Adobe Acrobat Reader DC has stopped working in Windows.