Multiple download failures of Firefox 117 through the Platform updater resulted in previous install corruption
The FirefoxPortable folder only contains the Data subfolder. The Other and App subfolders are gone.
So I can no longer try another update.
I'm currently downloading the *.paf.exe file manually (as there may be something wrong with platform updater because I'm also experiencing download issues with Google Chrome 64-bit) and will try to install it back that way.