Solved the problem!
I removed all plugins from my Resources folder. Only left Gizmo64, XPLM_64 and XPWidgets_64 (dll and so files).
XP11 finally successfully started and I was able to activate the TBM900. Then one by one brought back my plugins and at the end of the day I found the problem: SkunkCraftsUpdater. Still don't know what exactly does this plugin but as well as TBM900 runs smoothly on my XP11 I am 100% ok with that.
Best regards,
Julius