This is happening to me now in 2.5. The F1 window even said "fell through the world" twice.
It started that I made a chemistry station on a workstation, then added something else to the station as well (there was nothing in the production queue). Later after picking everything up from...
I have in the past installed multiple versions of 7dtd and played them separately.
Unless they'ved changed this, you should be able to re-download prior versions. Alternatively you can just save the current version in a different folder. (rename the folder)
In the past you would see the...
a17.2 (b27) confirmed this works
I have a17.2 (b27). Confirmed this works.
Note in my case I didn't see an immediate change in the timer and took some honey and an anti-biotic, then after a bit it just disappeared.
I had reached "illness 9H"...
Note -- be aware there are several different...