Hi,
There are points in your original topic I didn’t address. My free time is almost non-existent, so support for free plugins suffers, but I am trying to check more often what happens on www.remarpro.com.
1. The free plugin version uses a normal HTML upload form element, and it uploads files as they are. The Pro plugin has an enhanced upload (JavaScript-powered) that previews the file you want to upload, and it also performs a bunch of validations to see if the file is the right size or if the extension is allowed. It also has a whole system for control over allowed file types and for adding new file types. All that is going to remain in Pro version, because Pro version has many different attachments implementation, that has moved on from the Free plugin implementation years ago.
2. The error displayed when the file upload fails is received from the WordPress (for most of the upload errors), and it doesn’t provide any additional information to display – what my plugin gets from WordPress, that is displayed, there is no extra information provided.
After some testing, the Free plugin doesn’t suffer from the error display issue that was a problem with the Pro, so there is nothing to fix there. The point about showing errors still after the successful upload is valid, but, the errors are not visible to regular users (only topic author and admins see them), and the plugin doesn’t save timestamps for these events to know if the error happens before the successful upload. The only thing I can do is to add an option to remove upload errors the topic author or admin can click to clear the error. That will be added in the next update.
Milan