Ok. I use about 1500 mods but i will find it lol
That's why you start with just UC and the map, then add just mods that add productions and fillTypes on a new save. Leave the other 1300+ disabled. The vast majority of those mods are irrelevant to this test and can be ignored. Not sure how many production placeable mods you have, but 90% sure of of them is the culprit, especially ones that add new fillTypes.
In other words, out of your 1500 mods (at least from the list I saw), only maybe 10% of them could possibly be causing the issue. So, you don't have to test every single one.
The idea is to start with just one mod (the map), see if it works with only that enabled. Add a mod or two (only the types I mentioned above), try again. When it breaks, you know it was one of the last batch you just added. You could even do 5 - 10 at a time, at least it would narrow the range from 1500 to 10, which would be much easier to needle down on.
Edit: Or you could just wait until I finish the next version and see if it resolves the issue. No eta on that yet though, still a lot of RL things I'm dealing with. This is a work around for "in the meantime".
Depending on the way mods are programmed (script mods I mean), there's no way to guarantee compatibility with everything. I used to try to work around every single mod out there. Now, it depends. If compatibility means hours of "work around" code, then probably not. This looks to be late registered fillTypes (which are mostly obsolete in FS22), so I think the new version will address those. If they register too late, however, there's not much I can do. That's why you see ZZZ_ModName.zip instead of FS22_ModName.zip sometimes. Mods load in alphabetical order. The ZZZ_ prefix was the only way to ensure a mod was loaded at least after all the FSXX_ prefixed mods.
In other words, if a mod named something later alphabetically than FS22_TH and late registers fillTypes as well. That mod would most likely not work with UC or, at the very least, those fillTypes would be skipped. Just an example.