Possible problem repairing walls

[Daniel Nordström]

There might be a problem with PQ and repairing walls, as in they dissappear and you can build them again.

This is mostly a reminder for my self to check it thoroughly when I get the time.

[Jens Herrmann]

I know that problem...
After exploring architecture (? - German: Bauwesen) it isn't possible to build / repair walls.

[Christopher Crockett]

This is because civil engineering gives a a flat defense bonus which effectively obsoletes walls entirely. It's not very well documented, but it's the same in the base game