Running MBAM 1.41 paid on Win XP Pro SP3. Other security apps include AntiVir Premium, Outpost Pro (without using its IP Blocklist), and Zemana Antilogger. The program runs well with one exception. For the life of me I can't get the IP Protection to work. The error code that shows in the MBAM logs is (null) ERROR IP protection failed: PfMakeLog failed with error code 21. Any assistance in resolving this would be greatly appreciated.

Hi QBgreen, and welcome to Malwarebytes.org

Please see if this post on Fixes for Common Problems and Error Codes helps. In particular, look at solution #3 to have your Anti-Virus/Internet Security applications ignore/trust MBAM.

The following files need to be trusted

C:\Program Files\Malwarebytes' Anti-Malware\mbam.exe
C:\Program Files\Malwarebytes' Anti-Malware\mbamgui.exe
C:\Program Files\Malwarebytes' Anti-Malware\mbamservice.exe
C:\Windows\System32\Drivers\mbam.sys
C:\Windows\System32\Drivers\mbamswissarmy.sys

If this doesn't help, please let us know.

Does the regular MBAM protection start, and only the IP protection is failing?