Mega playscape upgrades

I destroyed mine to the point where only a few broken fences were left in the background. I thought this was the most destructed state and began to rebuild again. Everything worked fine except for the broken fences in the back, they just won't get repaired on both bases. So I teared them down again and made sure that all fences and decorations were gone. And now (after fortifying a couple of times) it's finally complete. Seems to me like we can't "repair" the broken stuff, only build up new things after destroying them completely.