If I deactivate all plugins the issue remains.
Changing to Twenty Seventeen does not resolve the issue.
If I migrate the database to a remote staging server using WP Migrate DB Pro, I receive the same error on the remote staging server when uploading an image there.
I have turned on debugging, which produced some errors about a plugin.
I deleted the plugin, now there are no errors, but the original image upload error remains:
“Sorry, this file type is not permitted for security reasons.”
