Gave experience book feature a try for the first time now, does it work for you?
Tried two different experience files, among them the in download included one, checking Experience Book (together with Experience Enabled) makes GUI (Fritz20) freeze in game playing. A first one game with a newly created experience file ran without problem, file was created but by reuse of the same file in next game reaching the first one position without entry (according to exp command) in experience, engine (and GUI) crashed, same with patricia.exp coming with download- bundle, regards