NicoKuroKusagi In my use case i had a very cryptic s3 user image link, and had to adjust the max length of the avatar url field to 150. It might be good to adjust this by default so that others do not have to look for this as a possible issue.
clarkwinkelmann NicoKuroKusagi are you using an extension to fill the field with an S3 URL? Or did you manually inserted it in the database? I don't think Flarum itself uses avatar URLs (instead of paths) natively so it's a bit of an undocumented feature at the moment.
NicoKuroKusagi I used Maicol07s SSO plugin and filled the avatar url link using it. Just as avatar URLs can be longer than 100 i would recommend adjusting that in a future release, could save people issues.