Please pardon the delay. I was partially right about the “ç” causing issues. It turns out the apostrophe was causing issues too. However, I believe the fault was on our side. Simply put, your name was mangled both when creating the C3DB entry for your account and when creating the directory for your account in the C3U cloud. I’ve fixed both places, and now you can log into C3U with your proper name, “L’Arçonneur”, and you can set your customs to download from C3U instead of from an external source. I put back everything I changed, so currently your customs still have external links. You can use your C3U control panel to remove the external links for the customs you have uploaded to C3U, and at that point the C3U download links should work fine. Note you will still need to upload any customs you’re hosting externally that aren’t yet hosted by C3U also.
Hopefully that’s all clear, but if you have any questions or you see any lingering issues, just reply back here or in a private message to me. In the meantime, I’ll add a task to the to-do list to stop this name mangling for any future accounts with non-English characters!