The reason is that the feedback button stores this information so that you can read it in sprintr. My guess is that it reads every userrole and puts the name inside a string attribute. However, because you have so many userroles that string becomes longer than the maximum length thus resulting in this error. If you want to get rid of this issue right away you could adjust the names of your userroles so that these become 17 chars shorter in total. Or if you have some time you could file a feature request to make this field larger in Sprintr.
On a side note, i would suggest to reduce the amount of enduser roles. configuring that amount of roles seems like a real pain to me.