For those who don’t want to upgrade, here is what I found out about the problem and how you can fix it yourself (as already posted in a different post):
The compiler threw several errors, the only relevant of them was:
‘std::vector’ has not been declared
After some searching I found
https://stackoverflow.com/a/38228651/1765341
which said that
#include <vector>
should always be used in classes that use vector.
After adding that line to 6 files that were in error, everything compiled fine.