I am having this same issue and am on level 3456 which requires the launching of a UFO. I had the issue on an earlier level but launched the UFO as a booster so I could eventually beat the level and move on since the UFO wasn't built into the game. I have tried following the directions provided with no luck.
Ugh @Lauraaa123 - I hope they are able to get everyone back to the correct level. I'm reluctant to try opening the game now in case I'll be stuck at level 1.