So, i have fully reinstalled windows (complete clear installation) and the problem persist. I have two suggestions:
problem is located in steam (where is stored player setting etc...)
i have another problem with starting leadwerks. Application throuh steam won't start, the i found problem with exe which request "Msvcr100.dll" (yes i have installed msvc++ redist) . I have downloaded this library and engine works
But fbx. models cannot be converted again and again...
When i use converter in folder Tools it works perfectly, only drag-n-drop system in editor not working.
And before (year before) all works perfect in this time i use 4.3 or 4.4 i dont know...