That has to be a mod problem. Did you change mods in the middle of a game?

This the build popup for a colony right ?

Reproduce the error and upload the output_log.txt file for review.

Since the game does not crash (it just closes the current screen), I don't think any "output_log.txt" is generated (I use to see a folder with the current date, but here, there isn't). Is one generated elsewhere (I'm in steamapps\common\Master of Orion) ?

Ok, I've managed to reproduce it 100% times:
It happens when I go to a ship building colony, and define its queue by spamming double click on my battleship (or any ship). The building list closes when I the queue is full, but as I spam double click (until it closes), I'm able to do one more double-click before the closing animation ends. When I do so, I see the building list glitching (it briefly appears again to restart the closing animation). There is no issue on this colony, but the issue comes on the next colony. On the next colony, when I open the building list, it instantly closes and sends me back to the galaxy view (so it closes the building list, and the colony view).
I have a save file to reproduce it, which also reproduce an other bug (I'll open a new thread about that). I'll give you the link in few hours.

Here is the save file (it is the same as the travel-speed issue):
https://drive.google.com/drive/folders/1ejTg5eOLSiCcniLnJLvBi4HukdlyXxz8?usp=sharing

To reproduce: Go to the bottom of the empire, in the Wasat system, the bottom planet. Remove the last battleship of the queue, and add a new one by double clicking twice (so 4 clicks). You should see a glitch since the closing animation restarts. Then go to any other system (Wolf, next to it for instance), go in a colony, and try to open the building list. Sometimes it just closes the building list (staying in the colony view), sometimes it sends you back to the galaxy view (closing the colony view).
What I've noticed is that you have to remove the last ship of the build queue to trigger the bug. If the queue is already full, and try to add a new ship (by double clicking twice), the bug doesn't occures. But if the queue is not full, the bug occures.

OK that is a different issue a lot of the screens I think would have closure issues like that, they did not code any defenses against stuff like that.

This is easy reproducible - following your directions able to cause it in my own game.

Bug.0.0.6.2a: Minor UI issue with the Build Popup and clicking on the build tiles while the screen is closing
Fix.0.0.6.2a: Just added logic to detect and prevent the reclusive calling of the close function on the UI