Rename 50_budgieremix.conf

[fossfreedom]

oops - the configuration file in /etc/lightdm.... is still the old name - needs renaming appropriately

[HEXcube]

I believe this issue's fixed by commit https://github.com/UbuntuBudgie/budgie-artwork/commit/dd1e90bf575d2b403668ae7ae1ad358c78a8b24c