Hello John, sorry about your problems. My name is Marco and I will do my best to help you.
Try this solutions to fix this:
Browser extensions can sometimes interfere with Gmail's functionality. Try disabling all extensions to see if this resolves the issue. If it does, you can enable them one by one to identify the problematic extension.
Accumulated cache and cookies can cause issues with Gmail. Clearing your browser's cache and cookies might resolve the upload error.
Ensure that the pictures you are trying to upload do not exceed Gmail's size limit and are in a supported format. Gmail has a limit of 25MB for attachments, and certain file types are blocked for security reasons.
An outdated browser can lead to various issues, including problems with uploading files to Gmail. Ensure your browser is up to date
If your Gmail storage is full, you might encounter issues when trying to upload new files. Check your storage and clear some space if necessary.
Sometimes, firewall settings or security software can interfere with file uploads. Temporarily disabling these might help identify if they are the cause of the issue. Remember to turn them back on after testing.
If the problem specifically occurs with drag and drop, it could be a browser-related issue. Some users have reported problems with drag and drop functionality in Chrome, which could be similar to what you're experiencing in Gmail.