This was an oversight which will be fixed in next minor patch.
Thanks a lot for pointing us to this problem!
Cheers

One can always construct a case which would not allow to unlock aspects when each unlock aspect moves the fence down by one.

Instead of changing the rules for such cases, we are exposing a new mutator next patch which allows to unlock aspects in any order as done in campaign mode or the Undergames.

We are going to

It seems like things are not like they look.
When I load the save game I find not cleaned up Banshee projectiles, which are blocking the Colossus from moving.

Not sure if this is still happening in the internal version, but seems what did happen is, that every exploded Banshee left an invisible obstacle behind which should have just been blown up when it detonated, but this unintended remaining blocks the movement of the Colossus (or any other unit trying to get past).

We need to find out how Banshees could leak such weird left overs that are physically blocking minions.

This issue will be fixed in next minor patch.

Thanks for reporting!

We will disable it for shielded props, but not for shielded units, because it would look wrong, if a shielded unit is totally ignored while it strikes all time.

We found the cause of this issue now.

It was happening when they were already standing on a moongate while trying to go through it or if they were repathing while on a moongate.

In this case they were not teleported but moved directly to the next step behind the gate, which most often made them run into a wall.

This problem will be fixed in next minor update.

Thanks for reporting!