Hello,
I'm using this version (copied from the 'about'-screen:
XnView MP Windows
Version 1.4.3 64bits (Feb 25 2023)
Libformat version 7.138
I installed XnViewMP64 Portable using the PortableApps-UI. The installation was easy, no errors, no problems. The application was installed with a German user-interface and runs smoothly.
I launched Tools->Options.
I set the language to 'English'.
I restarted XnVMP64.
The language was still set to 'German'.
I opened the Xnview.ini-file and changed the language manually from 'de' to 'en'.
I started XnVMP64.
Again, the language was set to 'German'.
I reopened the Xnview.ini-file and found the language-key still set to 'de'.
I double-checked this behavior. It is reproducable.
It seems that XnVMP64 does this change in Xnview.ini during its start-sequence.
The PortableApps-UI was installed with a German language-UI. I changed the language in some other portable apps without any problems.
Many of our apps automatically switch their language to match the PA.c Platform when launched from it. XnView and XnView MP are two of those that do. If you do not want this behavior, you can disable it within the PA.c Platform. Click Options and in the General tab look within the Language section. Uncheck the "Use this language for all portable apps" option ("Diese Sprache für alle Anwendungen verwenden" in German) and click OK.
Sometimes, the impossible can become possible, if you're awesome!