I logged on this fine morning too find 3 reviews 1 starred for two missions (there could be more with bugs but these two were ones played since yesterday when i checked last).
"When the war began" and "The Invasion of Hell" got crash reports in the reviews. One player stated "GS error" (which i know is something with nividia drivers i believe).
I was just getting 4-5 stars back in my once broke "The darkness war brings", lol I hope that one is bug free.
Indeed cooch99, the new patch has borked the Foundry and a good deal of the missions yet again, but hey, lets go to Vegas and party while folks that didn't pull their missions get a flurry of 1-starred ratings again. Thenwhen we get back, and alot of them have suffered unrecoverable damage in the rating system, we'll attempt to correct the issue, but let's leave the Foundry missions on for now, so we can gather more data on how another patch has caused another "EPIC FAILURE". I pulled mine, and I would suggest you do the same to avoid the risk of seeing more reviews like that on your mission.
I definitely recommend pulling them to authors with new missions, or you might face the possibility of 1 stars putting you in the lower tiers of the missions early, and hurt chance to get them seen and hurt the chance of getting a lot of plays.