You say about GLib 2.50 minimum requirement in 4.1.1 release notes. But seems like it was reverted: https://git.claws-mail.org/?p=claws.git;a=commitdiff;h=1445df7021764ede5cea62338e3724726006c413;hp=002826cb47c3b5ad8ec1692eb346bde70ac69837
Closing as INVALID because 1. This is a bug tracker, not a support forum. 2. You answered your own question. 3. A typo in the release notes is not a bug.