When adding a license, phone number and extension to a User, clicking Save gets the error: Failed at extension create.
Opening the browser console show the error: "SORRY, this extension (xxxx) already exists" Where 'xxxx' is the extension you are attempting to assign.
- 8x8 Admin Console
Possible workaround: Use a different extension number.
If the specific extension is desired, please create a support case so 8x8 Technical Support can investigate the cause of the error, and a possible solution.