Resolve errors related to the AcroCEF/RdrCEF processes of Acrobat or Acrobat Reader

AcroCEF.exe/RdrCEF.exe are inseparable processes of Adobe Acrobat and Acrobat Reader. They handle multiple integral aspects of the application, such as network interaction and Document Cloud services (Fill and Sign, Send For Signature, Share for View/Review, and so on). For more information, see

If these processes do not function properly, an error message is displayed while using any of the services dependent on the processes.

AcroCEF/RdrCEF error dialog

To fix the error, try the following solutions in the order they appear below.

Solution 1: Quit the Acrobat/Acrobat Reader application and relaunch it

  1. Quit the Adobe Acrobat/Acrobat Reader application.

  2. Open the Task Manager in Windows by doing one of the following:

    • Right-click on the taskbar at the bottom of the screen and choose Task Manager.
    • Press Ctrl + Alt + Delete keys on your keyboard and then choose Task Manager.
  3. If the Task Manager is not fully expanded, select More details.

    Task Manager

  4. Check if there are any AcroCEF/RdrCEF processes that are still running. If so, then choose the AcroCEF/RdrCEF process, and then click End Task. Repeat the step till no AcroCEF/RdrCEF process is running.

    End the AcroCEF/RdrCEF process

  5. Launch the Acrobat/Acrobat Reader application.

Solution 2: Safelist Acrobat/Acrobat Reader folder to prevent DLL injection in the AcroCEF/RdrCEF processes 

DLL injection refers to the interference or block of the functionality of the AcroCEF or RdrCEF processes by DLLs from third-party software. To fix this issue, add the Acrobat installation directory to the exception list of the third-party software. Once added to the exception list, the AcroCEF or RdrCEF processes work as expected.


The steps below explain how to add exceptions to Avast antivirus software. If you are using different antivirus software, follow the instructions on the respective website, and add the Acrobat or Acrobat Reader folder to the exception list accordingly.

  1. Open Avast antivirus. Click Menu and then click Settings.

    Avast settings

  2. Click General > Exceptions, and then click Add Exception.

    Add Exception

  3. Add path of the Acrobat folder as below:

    • For Adobe Acrobat: C:\Program Files (x86)\Adobe\Acrobat\
    • For Acrobat Reader:  C:\Program Files (x86)\Adobe\Acrobat Reader\
    Add Acrobat Reader folder to the exception list
    Example of adding Acrobat Reader folder to the exception list

  4. Click Add Exception. The Acrobat or Acrobat Reader folder is now safelisted.

If you are still facing the issue, analyze the ProcMon logs to identify the third-party DLLs loaded in the AcroCEF or RdrCEF processes, and then safelist the Acrobat or Acrobat Reader folder in the corresponding third-party software.

  1. Download the Process Monitor tool here.

  2. Launch the Process Monitor tool, and then click Filter > Filter.

    Filter for AcroCEF or RdrCEF process

  3. In the Process Monitor Filter, choose Process Name and type AcroCEF.exe. Click Add, and then click OK.

    Add AcroCEF or RdrCEF filter

  4. Launch Acrobat and then wait for approximately three minutes. The tool starts collecting the logs. Save the logs in PML format.

  1. Open the PML log file in the Process Monitor tool.

  2. Double-click the AcroCEF or RdrCEF process.

    Double click the AcroCEF/RdrCEF process

  3. In the Event Properties window, the Modules section lists the loaded DLLs. Check for any external DLLs that are loaded in the AcroCEF or RdrCEF process.


    External DLLs are DLLs not signed by Adobe, Microsoft, or Chromium.

    For example, in the screenshot below, a DLL by VMWare is loaded in the AcroCEF process. The rest of the listed DLLs are from Adobe, Microsoft, or Chromium.

    Third-party DLL

  4.  Add the Acrobat installation directory in the exception list of the corresponding third-party application.

  5. Collect the ProcMon logs again, and repeat the steps above for any third-party DLLs loaded in the AcroCEF or RdrCEF process.

Solution 3: Repair Acrobat/Acrobat Reader installation

  1. Open the application.

  2. On the application menu, click Help > Repair Installation.

    After the repair process is complete, restart your computer.

Solution 4: Uninstall and reinstall Acrobat/Acrobat Reader

You can sometimes resolve the error by uninstalling and reinstalling Acrobat.

  1. Uninstall Acrobat/Acrobat Reader from your computer:

    1. Open the Run command dialog by pressing the Windows key and the R key.
    2. In the dialog, type Control Panel and click OK.
    3. In the Control Panel, select Program and Features, and then select Acrobat/Acrobat Reader from the list of installed programs.
    4. Click Uninstall and follow the prompts to uninstall Acrobat/Acrobat Reader.
  2. Reinstall the latest version of Acrobat/Acrobat Reader on your computer:

    1. Go to the Adobe Reader Downloads page and click Download Acrobat Reader.
    2. Allow the Download Manager sufficient time to download all necessary installation files. Then follow the prompts to install Reader.


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