"This building is a university."

Translation: Ten budynek to uniwersytet.

[frandogk3]

Is it wrong to write "ten budynek jest uniwersytet"?

[Jellei]

Yes. In such a construction, you need Instrumental for "university". Or alternatively, you can say "Ten budynek to uniwersytet".

If you have any more doubts, you can consult this topic.

[JoshLovesBacon]

So "Ten budynek jest uniwersytetem" should be accepted?

[Kendra800150]

"Ten budynek jest uniwersytetem" is still being rejected.

[Thomasco3]

Zgadzam się z tobą.

[Olexsa]

"Ten budynek jest uniwersytetem" nie jest akceptowane.

[Jellei]

I'm removing this sentence, it's kinda nonsensical. It's not very probable for a university to fit inside just one building.