With WinDbg I got more information:
(a58.df4): Access violation – code c0000005 (first chance)
*** ERROR: Symbol file could not be found. Defaulted to export symbols for C:\tobiisdk\tobii-analytics-sdk-3.0.83-win-Win32\Cpp\Lib\tetio.dll –
tetio!tobii_sdk_vector_set_string+0x2e94:
but still have no clue what is the actual error