So I did an upgrade from 42.3 to Leap 15 as described in the OpenSUSE Wiki (removed all the extra repos and so on) and got to admit it was not a smooth ride. Some of the problems were expected and dealt quickly (like Nvidia drivers), but I'm trying to cope with one that is extremely annoying:

After the upgrade locales went to town. Some apps run in English, some in Polish (as they should)... It was a mess. I've opened Yast and reset language and keyboard to Polish. It made things worse - after restart more apps run in English and I've been asked whether I want to convert all folder names to English (so Dokumenty would become Documents and so on). Insync crashed on start.

locale command gave this in first 2 lines:

locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directoryFor the time being I've went to sysconfig editor in Yast, opened System -> Environment -> Language and set following variables to pl_PL.UTF-8:

RC_LC_ALL
RC_LC_MESSAGES
RC_LC_CTYPE
RC_LC_COLLATE

Input method, time, numeric, monetary, paper are unset.
Seems to have fixed the most annoying problems. FOr the time being it seems that only nvidia-settings start in English.

Would love to hear your input what else I should check to clean this mess.

Another, this time minor one (hopefully), I've noticed is that upon boot I get coretemp errors (adding core 8-15 failed). Any ideas while it throws this for the 2nd processor?