I am stuck in tour 1 mission 4 or OP 4. Even though I have now completed mission 4 (and OP 4 whatever that is) multiple times I can not progress. I have not turned on any cheats, I have collisions on and all.

Is this a known problem? How can fix this?

Thank you

X-wing or tie fighter?
You might need a pilot editor, either to roll back to a previous mission and hope the problem doesn't present itself again or to skip to the next mission.
This one is for X-wing:
https://github.com/j-mathes/X-Wing-Pilot-Editor

I had a similar issue in TF, a glitch made me skip a mission entirely so I had to use an editor to roll back and play it.