adobe acrobat cannot open in protected mode due to an incompatibility with your system configuration

This error usually means Acrobat’s Protected Mode security feature is conflicting with a Windows setting, security program, or system configuration. Since reinstalling and repairing Acrobat didn’t help, I’d try these steps:

1. Update Acrobat: Open Acrobat and go to Help > Check for Updates, then install any available updates.

2. Check third-party security software: Temporarily check whether your antivirus or endpoint protection is blocking Acrobat. Don’t disable your security protection permanently.

3. Check Windows compatibility settings: Find the Acrobat shortcut, right-click it, select Properties > Compatibility, and make sure compatibility mode isn’t enabled.

4. Check Acrobat’s Protected Mode settings: Open Edit > Preferences > Security (Enhanced) if Acrobat allows you to access the settings. Make sure Protected Mode at startup is enabled. If Acrobat won’t open at all, skip this step rather than changing security settings through registry edits.

5. Check for Windows updates: Install pending updates and restart the computer.

Adobe’s official troubleshooting guide is here: https://helpx.adobe.com/acrobat/kb/protected-mode-troubleshooting.html

I’d avoid permanently disabling Protected Mode or making registry changes from random online guides, because Protected Mode helps protect your computer from malicious PDFs. If the problem continues, Adobe’s troubleshooting guide includes more advanced checks for system configuration and security software conflicts.

I did the repair and it worked.

There is a key under HKLM/SOFTWARE/POLICIES/ADOBE/ACROBAT/DC/FEATURELOCKDOWN 

Here ensure bUseWhitelistConfigFile value is present , it should be a DWORD value and value should be set to 1.

Hi @Grinbit 

Sorry to hear about the trouble caused.

Does Acrobat open even for a couple of seconds or crash immediately? If you can launch it, then, 

• Navigate to Reader>Edit>Preferences>Security (Enhanced)>disable "Protected Mode at Startup" and "Enhanced Security">OK>Reboot Reader [Windows only]

Note: these changes are only for testing purposes. Once tested, please change it back to the previous setting.  

• If you have any antivirus installed, then disable it for a while.

If nothing works, then, 

• Run this cleaner tool to remove the existing installer and application’s file traces:

https://www.adobe.com/devnet-docs/acrobatetk/tools/Labs/cleaner.html

Download the Acrobat Reader installer from here:

https://get.adobe.com/reader/enterprise/

Thanks,

Akanchha