Hello,
in my library I found this entry:
There's actually just one version of Reflow, and it presents the language in the UI based on your Mac Language preference.
I've seen this happen when switching between languages on Mac.
Try this:
1. open your Mac Language & Region preferences
2. select English as your preferred language
3. run Reflow (it should show up all in English), then quit Reflow
4. go back to preferences and select German
Reflow should now show just English in the user interface. No reboot, uninstall, reinstall, or clean is required.
On the other hand there is a German "cookbook":
Dazu öffnet man im Ordner, in dem PSE gespeichert ist (üblicherweise "Programme/Adobe Photoshop..."), den Unterordner "Locales > de_DE > Support Files". Hier findet man die Datei "tw10428.dat", die man in ein anderes Verzeichnis verschiebt (nicht kopieren, die Datei muss aus "Support Files" entfernt werden). Beim nächsten Programmstart von PSE erscheint die Programmoberfläche englischsprachig. Die deutsche Version gibt es wieder, wenn die Datei "tw10428.dat" an ihren alten Platz zurückgelegt wird.
And here my try to translate it in English:
For this, open the folder where you saved the PSE is (usually "Program Files / Adobe Photoshop ..."), the subfolder "locale> en_US> Support Files". Here you will find the file "tw10428.dat" that you move to a different directory (do not copy, the file must be removed from the "Support Files"). Next time you start PSE from the program interface appears in English. The German version is available again if the file "tw10428.dat" is put back to its original location.
Good luck!
Hans-Günter