On 11 Dec 2021, Alisha Stutz said the following...
 
 AS> Hi g00r00,
 AS> 
 AS> I am trying to install MysticBBS in /mystic as described in
 AS> unix.install.txt.
 AS> 
 AS> sudo mkdir /mystic
 AS> sudo chown mystic:mystic /mystic
 AS> ./install

What I did, is I have a mysticbbs user.  I unpacked the installation archive into /tmp and when I installed the BBS software itself, I had it install into /home/mysticbbs/bbs directory and the installation went off without a hitch.  It sounds like what the installation utility needs is an option to install into an already existing directory if it is available (defaulting to NO of course).

... A program is used to turn data into error messages.

--- Mystic BBS v1.12 A47 2021/09/29 (Linux/64)