I'm not sure what's the source of this behavior, every time I open a GUI of a search light the mod LTN Manager stops working, it won't show it's GUI again.

Once this happens, there's a high chance that running /LtnManager refresh-player-data as its author suggests will take the server down with Attempt to index local 'translations' (a nil value), some times the problem will be the dictionaries variable.

I just tried a new game offline only with SearchlightAssault 2.1.0, LogisticTrainNetwork 1.16.7 LtnManager 0.4.12, and it happens just as I mentioned.

Steps to reproduce:
1. Add any LTN station to enable LTN Manager which is by default opened with CTRL+T.
2. Test LTN's GUI and then place a search light and interact with it
3. Check that LTN Manager's GUI won't open any more
4. Now the command /LtnManager refresh-player-data will some times repair this, but very often breaks the game with the errors mentioned earlier. (Without search lights it won't break)

Tried to edit it.
Wow, I really can't delete my own messages in these boards?

Thanks for your report, it looks like I should be able to make an update fixing this soon.

I have released version 2.1.1 which should fix this issue.

I wasn't able to figure out how to get the 'pinned' feature of the LTN Manager to work quite as expected, but at least it can be reopened now.
Please let me know if you notice any other GUIs misbehaving -- I had to change a couple things on my side that I'm iffy about. I haven't read a lot of gui code from other mods yet.

The new version should start to appear in the mod portal shortly.
If you don't see it in-game you can download it manually here: https://mods.factorio.com/mod/SearchlightAssault/downloads