Blackfell refinery permit instant failure, not sure why?

[FlavorlessGum]

We did a lvl 45 blackfell refinery permit and after setting up our defenses quite deep we got an instant failure. As in, the second it went from build defenses to start it just failed with no mob spawns and I am not sure why. Any ideas?

[het-terika]

Happened to me again today.
Earlier we were building defenses like cars, flamethrower and turrets and as soon as we started it showed purification failed. We thought it was possibly because any of our defenses clipped with the production facility and as soon as we started a lot of damaged was dealt due to clipping.
But today we didn't build anything near the purification facility. We just blocked the entrances to the building and it failed twice in less than 10 secs. First time it failed in 4 secs and showed purification progress to be 35%. Second time it failed at 9secs with progress at 40%. Both the times waves had just spawned, just as it spawned and we were about to shoot they disappeared and showed purification failed.
Another is that we were continuously doing the purification and it failed after 7-8 successful purifications with the same defenses built.

[Goddess of Dorkness]

Happened to us today and yesterday as soon as it went from build defenses to starting the purification. Any solutions?