Update, Fixed error.
Well that was fun, the game started throwing an error that wasn't an error before, and still shouldn't be. Even after reverting the mod to the old working version, it still gave the error, ha. Luckily I figured it out and removed the offenders, namely Apadana. Commented out Hermitage as well, just in case, but this one defaults at 4 and wasn't changed, so it doesn't matter.

This is now causing crashes since the most recent update. I can't start a new game with this installed :(

Ok, sorry I didn't do this sooner, but I took out the museum of art / artifacts by default so it won't affect the theme bonus for some.
They can still be 'uncommented' inside the .sql if you want to change the numbers

牛逼，奇观全有槽位，后期你将拥有一百多亿个槽位，多少搞艺术的人来了都得给塞进去，文化胜利界的龙卷风摧毁停车场，然而同上~不知何故艺术博物馆不能凑主题了，辛苦作者一个一个奇观地设置

It doesn't change the themes at all. It leaves the museums at the default of 3 slots. I haven't seen this issue, but I'll try to look at it later.

This mod does not apply themes to Art Museum. Is this intended?

Can you describe what issue you are having?

It is working fine for me and everyone else. I just checked it again in a new game.
If it's not working for you, then you are probably missing one of the main DLC's, which the mod says it requires.
In the description, I say to delete the Wonders in the DLC section if you don't have them.

not work