As I mentioned in a previous post, hq2_5 had a teleporter that didn't work. I looked into it and saw that there was in fact a trigger_teleport in place, but the target didn't exist.

I tried showing hidden objects, but the info_teleportation_target didn't appear. I thought maybe the RMF file got corrupted or just didn't work with the Spirit of Half-Life FGD file. I started Worldcraft and opened the original hq2_5.rmf with the standard Half-Life FGD file. Nothing.

I decided to check the old exported hq2_5.map file and opened it in Hammer. And everything was there :D

It turns out... I worked with the MAP file back then. Normally you'd work with RMF, export to MAP and compile that to a BSP. But you can work with MAP, and I remember doing that for whatever reason (laziness, probably). I think some things aren't supported in MAP or whatever, hence it's better to save it as RMF, but really, I don't know the difference anymore.

Anyway. I saved the map as hq2_5.rmf, exported it again as hq2_5.map, compiled it and saw that everything worked again in-game.

Phew :D

I've posted most of the known issues in my github project (8 so far) and this was the first one that I marked as resolved. Feels good :D

Now I'll continue testing HQ2 and keep in mind that I probably worked with MAP files more than just once...