Without more information it's hard to diagnose the issue. When there is a conflict between two Plugins it's not necessarily the last one to be activated that is causing the issue.
If you had installed WP Content Filter THEN the other one and got the same problem you would likely think it was that Plugin causing the issue because it was the last one you'd activated. It's not always that simple.
Can you try activating WP Content Filter and disable the other one. Still get issues?
If you don't then there is an issue with one of the Plugins but without more specific information I can't diagnose the problem.