I get a “Couldn’t open file! Unexpected end of ZLIB stream.” message when I try to install it.
Just wanted you guys to know.
Hi, thanks but please see/update https://www.quaddicted.com/forum/viewtopic.php?id=266
Oh, thanks. That worked 
What worked? I really want to find the cause of these errors.
The suggestion in that other thread to delete the zip in the download folder and dl again.
I think what might cause this error to happen in the first place is trying to install something while another install is still running.
When I first tried to get mapjam3 I was installing mapjam4 at the same time.
Maybe something to do with that.