Hi,
- about the maxmind error in your log, what to do is detailed here: Configuring MAXMIND for reverse IP lookups
- about the fact that your are not able to upload png, this is not a limitation a discourse, (unless it’s voluntary), something is wrong somewhere
Considering the error message I don’t think this is linked to TL (did you try as an admin?), component or authorized extensions (https://your.domain/admin/site_settings/category/files?filter=authorized). Perhaps something on your host is preventing an upload (max size?), what kind of install do you have?
ps. just saw your other post, you can also try to upload something here: https://try.discourse.org/