Error when granting access to a report to a user

Previously, to grant access, I simply copied the mail and pasted it, and it started to give an error since yesterday. And now I just enter the first 2-3 letters of the mail, the desired user is displayed and so I add, and there are no problems and errors.
Out of habit, I didn’t even try to enter only the beginning of the mail, but simply copied and pasted it. Perhaps the problem is not in this, and this is not a solution, but at my stage the problem is solved.