All tags disappear

All my tags disappear after building the game. This leaves my game useless. I found this in the editor:

Clicking the “tags” menu on a game object:

44356-tags-1.jpg

Clicking “Add Tag…”:

44357-tags-2.jpg

What’s going on? And why are my tags different from level to level? Most importantly, why do my tags disappear after building the game?

I solved this by taking a photo of the tags, and re-adding them to the tags list. Everything is working ok now.

44387-tags-3.jpg

Better solutions are still going to be upvoted or accepted.