Upgrade tool from 21.3 to wilma half way through install shows in what looks like chinese text...bit offputting

[zzsimonb]

please see enclosed screenshot
its installed okay and reverted back to uk english, so no lasting effects.

[rcalixte]

This is very likely due to the system font being updated or removed while in use. Artifacts are expected when this happens and usually a reboot will resolve it.