A running instance of Acrobat has caused an error

In this post, we will show you how to fix A running instance of Acrobat has caused an error message. Some Adobe Acrobat users have reported that while using the app, they get this error message. It is specifically triggered when users try to use some tools and features in Acrobat.

The primary cause of this error is the fact that there is already an Acrobat instance running and you try performing an operation outside Acrobat. Suppose, there is already an instance of Acrobat running but is busy or in a hang state. Now, when you try to perform a task like opening a PDF in Acrobat by double-clicking it from File Explorer, this error occurs. If you are also experiencing the same error, we got you covered with all working solutions. So, check out below.

A running instance of Acrobat has caused an error

If you are getting A running instance of Acrobat has caused an error message when trying to use a feature or tool in Acrobat, you can use the following solutions:

1. Close Acrobat and terminate all running Acrobat processes.
2. Make sure you are using the latest version of Acrobat.
3. Repair the Acrobat app.
4. Temporarily disable your antivirus.
5. Try this Registry hack.

1] Close Acrobat and terminate all running Acrobat processes

The first thing you can do to fix this error is to restart the Acrobat app. For that, you first need to quit the Acrobat app and make sure there is no Acrobat process running in the background. Here are the steps to do that:

First, close the Acrobat Reader app. To do so, click on the Menu option and select the Exit Application option.

Or, simply press the CTRL + Q hotkey to close Acrobat.

Now, open the Task Manager using CTRL+SHIFT+ESC and make sure there is no Acrobat process running in the background.

You can check under the Apps and Background processes sections. If there is an Acrobat process, select the process and press the End task button to close it.

Once done, restart the Acrobat Reader app and check if A running instance of Acrobat has caused an error is fixed.

Read: Adobe Acrobat Error 110, The document could not be saved.

2] Make sure you are using the latest version of Acrobat

If you are using an outdated version of Acrobat, you are likely to run into errors and issues like this. Hence, if the scenario is applicable, update Acrobat Reader to its latest version and see if the error is gone. Here are the steps to do that:

• First, open the Acrobat app and click on the Menu option.
• Now, go to the Help option.
• Next, select the Check for updates option.
• Acrobat will now check for updates. If available, follow the prompted instructions to update Acrobat.
• Once done, relaunch Acrobat and check if the error is gone.

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

3] Repair the Acrobat app

If your Acrobat app is corrupted, you might get the “A running instance of Acrobat has caused an error” message when using a tool. Hence, if the scenario is applicable, you can repair Acrobat and see if it works. Here’s how:

• First, open Acrobat and click on the Menu option from the top menubar.
• Now, click on the Help > Repair installation option.
• Acrobat will repair itself and will be restarted once the process is finished.
• Check if you have stopped receiving the error now.

In case you are unable to use Acrobat due to this error, you can repair Acrobat via Windows Settings using the below steps:

• First, press the Win+I hotkey to open the Settings app.
• Now, go to the Apps tab in the left-side pane and select the Installed apps option.
• After that, tap on the three-dot menu button associated with the Adobe Acrobat app and choose the Modify option.
• Next, in the opened window, choose the Repair option and click on the Next button.
• Lastly, press the Update button to start the Acrobat repair process. When done, you can reopen Acrobat and see if the error is resolved.

Read: Adobe Acrobat Reader installation stuck at 90%.

4] Temporarily disable your antivirus

If you are using a third-party antivirus, check if it interfering with Acrobat. You can temporarily disable your antivirus and then try using Acrobat. If the error is fixed, you can be sure that your antivirus was causing the error. In that case, you can add Acrobat to the exception or exclusion or whitelist of your antivirus. If that doesn’t help, report the issue to your antivirus vendor.

5] Try this Registry hack

The Adobe support team has recommended using a Registry hack to get rid of this error. It is as follows:

You can first back up your Registry to avoid problems in the future.

Now, close the Acrobat app.

Next, press Win+R to open the Run command box and enter regedit in it to open the Registry Editor app.

After that, in the address bar, enter the below address:

HKEY_CLASSES_ROOT\acrobat\shell\open\ddeexec\application

Now, right-click on the application key and choose the Export option to create a backup of this key.

Next, double-click on the Default key from the right-side panel.

In the Edit String window, enter AcroViewR20 in the Value data field. After that, press the OK button to save changes.

Finally, close the Registry Editor app and restart the Acrobat app to check if A running instance of Acrobat has caused an error is fixed.

Read: Adobe Creative Cloud Installer failed to initialize error in Windows.

That’s it. I hope this helps!

What is error 0xc0000142 in Acrobat Reader?

The error code 0xc0000142 occurs while launching Acrobat Reader. When triggered, you will get an error message saying “The application was unable to start correctly.” This error is usually caused due to corrupted system files. So, if you get this error, run SFC and DISM scans to repair system files. Also, ensure that you are using the latest version of Acrobat.

How to fix suspended installation errors for Acrobat on Windows?

To fix the suspended installation errors while installing or uninstalling Acrobat, you can stop any ongoing installations and then try installing Acrobat. To do that, you can open Registry Editor, go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer, and delete the key named Inprogress. If that doesn’t help, unregister and re-register the Windows Installer service and then try again to check if the error is fixed.

Now read: Adobe Acrobat Out of Memory error.