I have the exact same issue as OP.
installed WoT and it is in English.
Installing the new version as OP has done i get the exact same issue.
Everything is in Polish.
Uninstalling the addon makes WoT go back to English.
So yeah there is an issue with the installation
xvm.log
As u can see it sees the Language as Polish on xvm, yet i installed it in English.
_Aslains_Installer.log