@saglix We are really sorry to hear that the plugin is not working for you.
Regarding the deleted images, you can always restore the original file as WP Paint doesn’t delete the original file and saves the file as a copy. Please click on Edit With WP Paint and click on Restore Original to get your original image back.
Also, can you check your server settings if the following have been set correctly:
1.post_max_size
> Should be at-least 2x size of the image being edited
2. upload_max_filesize
> Should be at-least 2x size of the image being edited
3. allow_url_include
= Should be On
4. request_order
Should be set to ‘GP’
We have a very small fraction of users who are facing this issue which we are working on replicating and fixing. It would be helpful if you could provide the list of plugins that you are using in your environment so that we could try and replicate your environment and test it.