When you optimize an image with ShortPixel Image Optimizer, you may receive the message “Could not create backup. Please check file permissions”.
There are two possible causes for this issue.
Inconsistent data migration #
Version 5.0 brought many new features, including a new way of storing the optimization information that prevents other plugins from accidentally removing it (which in most cases resulted in the same image(s) being optimized again). For this reason, when you upgrade, you will probably receive (or have already received) a message asking you to convert the legacy data to the new format. If for some reason this process is not done correctly, the optimization data can become inconsistent, and one of the most common consequences is the “Could not create backup” message. To fix this, proceed as follows:
- Go to Settings > ShortPixel > Tools (to access this menu you’ll probably need to have the Advanced Mode enabled).
- Click on Search and Migrate All.
- Wait for the process to complete.
Click on the Finish Bulk Process button.
Now try the optimization again and the error should not appear!
Wrong permissions #
The second cause could be that your folders or files have the wrong permissions. Please read this article to learn more about it: Why can’t the plugin overwrite a file or create a backup? What are the necessary permissions?
More causes #
If you still need help, please read this article on all possible causes and troubleshooting methods: Why some or all of the images cannot be optimized?