My app is complaining that it can’t find a shared library, e.g. libgfortran.so.1 could you please install it?

We would guess that 9 times out of 10, the allegedly missing library is there. The problem is that your application is looking for the version of the library that is compatible with the old system software. It will not help to point your application to the new libraries. They are more than likely to be incompatible with the new system and we won’t help you debug any problems  if you try to do this. The correct solution is to reinstall your software. If the problem persists after the reinstallation, then please contact us and we will install standard libraries that are actually missing.