It didn't help but reinstalling everything time and time again, fixed it... but there is a new issue...
for a new thread..
Phil, wanted to say, that
1) if you want to get rid of the error, you can switch the debugger off
2) if you're using Lazarus-SVN then you need to update the Lazarus and rebuild it, because the error was fixed in SVN version. If you don't use SVN, but still want to get the latest, you can use daily snapshots.
3) if you're using SVN (or daily snapshot) but still getting the problem you need to bug report it and
attach the debugger window output.
(all 3 points are discussed in the thread pointed by Phil)