System is not allowing to edit some Time categories

Summary:

Hi experts,

While trying to update the some Time categories, especially that are loaded, it is giving me the below error:

Unable to retrieve content. Additional information for "Remote Region error #3":

The Time Categories task couldn't be called. Review the FunctionalSetupServer logs for more details on this error. Contact your help desk..

Note that it is not happening in all the loaded time categories, only some. We also removed the Time category from all the Rules, but still it is not allowing us to do any update. We are approaching time category method for the ease to update them anytime, and this will create a lots of problem, if it doesn't allow to update.