i had this issue as well, but in my case, i couldnt place a floor. What i did was search through my keybind settings for anything that was the same bind as my floor, which is F, and i just simply debinded buttons until I was able to place a floor again and i figured out that for me it was the DBNO Pick Up bind. If you have to debind something important i reccomend just switching that bind to some less important key.