So, this only happens for me when I add a PPA that does not have a Release file. (In this instance, dolphin-emu.org's PPA). I tried on another PPA that also does not have a release file and can replicate the error as well.
Disabling that PPA resolves the issue for now.
So, this only happens for me when I add a PPA that does not have a Release file. (In this instance, dolphin-emu.org's PPA). I tried on another PPA that also does not have a release file and can replicate the error as well.
Disabling that PPA resolves the issue for now.