Every time I upload it it brings an error message and I can't click anything else. Does anyone know how to upload a map, or why this is happening?

After saving and renaming the map, click "Publish". If prompted to "update existing" or "publish new," click the latter. Click "yes, go to the steam page". On the steam page, scroll down and change the visibility to public. Also, make sure you're subscribed to the map.

引用自 Bazinga：

I can't upload my map? Every time I upload it it brings an error message and I can't click anything else.

Every time I upload it it brings an error message and I can't click anything else. Does anyone know how to upload a map, or why this is happening?

I merged these two because my answer should also fix your problem.