Image Uploading Issue | WordPress.org

There might be some plugin conflict causing this. Please try deactivating and activating plugins one by one. If that does not fix it then try to update the WP version to the latest; if not done yet.
Try to see in the console if there is any error generated or not.

Okay so I disabled a theme plugin, seemed to fix the feature image issue and the former issue with error message was due to my file dimensions being too big. Thanks for the help!