@laserstore If a 500 error is issued, this is a server error. The plugin works properly. Because of this, other plugins may not work correctly for you and generate errors. This applies to various ajax queries.
What should be done in such cases?
1. If you know how to do this, then look at the server logs, there are all the errors.
2. Contact the technical support of your hosting provider and justify the problem. Find out where the server logs are located (if you do not know the log is stored). Ask to fix the problem, maybe they will fix it.
Only after we see the server logs, we can find out what is the reason for the script to work incorrectly. You can find an alternative to my plugin, but keep in mind that something on your server does not work correctly.
Be sure to write here if the error has been fixed. There are other people who will use my plugin and should be properly informed.
Among other things, another update will be released soon, bulk generation SKU by categories will be available in the free version. More options will be added.