I've detected tool's crashes on try open inventory of character that wields new enhanced TaXis rune (others 'xxx'Xis runes will cause the same behavior, i think).
Shorter report message:
Unhadled exception .
Unhadled exception on adress 0x6A0B9854 (QtCore4.dll) in MedianXLOfflineTools.exe: 0xC0000005: access denied on read at adress 0x00000000.
Debug stops in IL-code at that string: "6A0B9854 mov eax,dword ptr [eax]"
May that helps in development somehow.
Sorry for bad English, btw.
EDIT: Also crashes by every !weapon! item, that's aquired in new patch (because of DEX/STR bonus changes, imo). "Old" characters re-saved in new game but without new items still can be operated correctly.