I confirmed the 2.7.0.14 GOG patch will install over itself, rather than give an error about the game already being up to date (possibly because of the LanguageSetup.exe error the first time, which I also got). However, the 'incorrect version' errors simply mean the files were already updated, and so not what the patch was expecting. No files in the D:OS install folder are changed or removed when running the patch again, so you can just ignore the errors.