Sorry, you are not allowed to upload this file type.

Hello,
This may be a protection mechanism of some security plugins or some rewrite rules that prevent PNG image from being uploaded.
To test it, please make sure the get_allowed_mime_types function returns an array of file extensions that includes PNG.
Best regards

The file was a jpeg. This is not a exmage issue. I disabled it and the issue persists. Thank you.

Ah I see.
I mistook the file extension of the image you sent above.

I have the same problem:

Sorry, you are not allowed to upload this file type.

I added this line to wp-config.php but it did not help:

define(‘ALLOW_UNFILTERED_UPLOADS’, true);

Hello @rjrjrjrj,
Is your site a WordPress multisite?

I have no idea what multisite is

Can the same image be uploaded normally when our plugin is inactive?