@shpxlbh You might want to double-check that the plugin is active. Otherwise, it could be a separate issue. In that case, you could try deactivating all plugins and switch to the Twenty Seventeen theme. If uploads work after doing that then the issue is probably caused by something you deactivated.
Gravity Forms provides support to customers so if this is somehow related to their plugin then I’m sure they’ll be glad to look at it for you.
PS. Consider opening a support request if you ever have an issue with a plugin in the future (before rating it poorly). Help is available a lot of times.