it works fine with no mods loaded. can you tell me where I can get help with the .rpt file?

same here. It still doesn't work.
the steam workshop missions I subscribed to lose the savegames and also don't even show if you finished a mission.

to recreate missing savegame:

1. subscribe to a user made steam workshop mission
2. start playing the mission and save it somewhere inbetween
3. exit ARMA 3
4. start ARMA 3 and try to load the savegame

to recreate missing mark for finished mission:

1. start workshop mission
2. play it all the way through and finish the mission
3. sometimes (not always) it doesn't show the green mark for when you ended a mission

as long as this issue excists I can't use steam workshop at all becuase it is really frustrating to always start a mission from the very beginning if close out of ARMA 3

besides my savegames go missing I also have a huge FPS drop after playing for an hour or so and loaded a savegame because I died. It's funny because I have regular framerate when I stand still (40-50) and it drop und 10 when I am walking with my player mannekin