**Steps to replicate the issue** (include links if applicable):
* Go to https://en.wikipedia.org/wiki/Special:EnrollAsMentor
* Type any introduction message (including none)
* Click "Enroll"
**What happens?**:
* An error message comes up saying "Introduction message is too long (affected user ID: 49604360). Maximum length is 240."
* The exact same error occurs (with a different user ID) whenever I try to edit the information of (screenshot below) or remove a mentor.
**What should have happened instead?**:
* I should have been able to enroll as a mentor/edit a mentor/remove a mentor — the introduction messages are not over the limit, and regardless it should not affect the ability to remove a mentor.
**Other information** (browser name/version, screenshots, etc.):
* I am using an English Wikipedia administrator account on Firefox 139.
Trying to enroll as a mentor:
{F63634027}
Trying to edit a mentor:
{F63634110}
This is my first bug report, so apologies if I have done something wrong.