In 1.68 I find these error messages in my RPT (dedi server RPT that was, no mods or addons used)

10:40:09 Error in expression <on>
10:40:09 Error position: <on>
10:40:09 Error Undefined variable in expression: on
10:40:09 unable to compile MFD condition on
10:40:09 Error in expression <mgun>
10:40:09 Error position: <mgun>
10:40:09 Error Undefined variable in expression: mgun
10:40:09 unable to compile MFD condition mgun
10:40:09 Error in expression <missile>
10:40:09 Error position: <missile>
10:40:09 Error Undefined variable in expression: missile
10:40:09 unable to compile MFD condition missile
10:40:09 Error in expression <ils>
10:40:09 Error position: <ils>
10:40:09 Error Undefined variable in expression: ils
10:40:09 unable to compile MFD condition ils

I'm not sure which vehicle causes it, might be O_T_VTOL_02_infantry_grey_F