That indictates there is something in the hand histories that PAH can't understand.
If you're not already, please use the latest PAH version
1.19.6.
If you still see the error message, close PAH and your poker sites.
Have PT2 import everything up to date, and stop the imports.
You then need to make sure all the processed hand histories are cleared - hopefully you have the "move processed files to" option checked where it is available (stars and FTP?), so this should be done automatically, but you can check that the HH folders are empty.
For Prima, you need to use the 'Reset DBs' option on the auto-import tab - this will empty the HH DB that prima writes, so make sure you've imported everything from it first. (You should do this periodically anyway - I do it at the end of every day after I've closed the poker site and the import, then forced an import just to make sure).
Then start up PAH again, you shouldn't get the error.
I suggest that after this you try one site at a time to start with, so that if you do see the error again you can identify which site is causing it.