I’m not sure if the filter is actually causing you to be unable to play, but if you suspect that’s the case, you can disable it out of game.
Locate the following file:
C:\Users\[Windows user name]\AppData\Local\Funcom\Anarchy Online\[hash]\[AO directory]\Prefs\Prefs.xml
Open this file with your favourite text editor, e.g. windows notepad. It should look something like this:
The lines under ChatFilterRules are your chat filters (in my sceenshot lines 4, 5, 6, 7). Delete the ones you wish to remove.
I would recommend making a backup first when editing your preferences.