Why do I get sandbox violation error only in MP missions?

[karpiyon]

Hi, I am developing a mod and i need to write some data to the mod log. In SP there is no problem however, in MP I get This error:

LUA (Main): Scripting -> io.open(w)(C:\Users\UserName\AppData\Local\Temp\janjanComm.txt): sandbox violation

Where can I R/W to in MP? Will DCS saved games folder be ok?