i installed 3 of these boards on sunday and the layout of files hasn't changed much in 20 odd years, permissions and ownership were the biggest issue but i also moved everything out of cgi-bin & public to just 1 folder (cgi-bin is pretty much obsolete now)

i still have these releases 

/backup/older-backup/recovered/basehome/ftp/AnyOS/forums/yabb/Y1Gold_Release_cgi
.zip
/backup/older-backup/recovered/basehome/ftp/AnyOS/forums/yabb/Y1Gold_SP1.1_cgi.z
ip
/backup/older-backup/recovered/basehome/ftp/AnyOS/forums/yabb/YaBB_1Gold_SP1.3.2
_cgi.zip
/backup/older-backup/recovered/basehome/ftp/AnyOS/forums/yabb/YaBB_2.1.zip
/backup/older-backup/recovered/basehome/ftp/AnyOS/forums/yabb/YaBB Manual.pdf

anyway this solved the problems i see even on this board so rather than set everything to 0777 & 0666 use this...

if you're unable to do this yourself i can do it for you but i will charge, while i'm there i will change every instance of yabbforum.com to yabbforumsoftware.com as well (there's a lot) even on this board and that's not a good look

 # Add user to apache or www-data group

 # On RHEL/AlmaLinux/CentOS:
 usermod -aG yourusername apache

 # On Debian/Ubuntu:
 usermod -aG yourusername www-data

 # 1. Set the owner to your SSH user, and the group to your primary group
 chown -R yourusername:yourusername /path/to/userdir

 # 1.1 restart apache
 # rhel
 systemctl restart httpd
 # debian
 systemctl restart apache2

 # 1.2 cd to forum/dir

 # 2. Set standard secure permissions (775 for folders, 664 for data files)
 find . -type d -exec chmod 775 {} +
 find . -type f -exec chmod 664 {} +

 # 3. Apply the SGID bit to directories
 # This forces all NEW files created by YaBB/Apache to inherit your group!
 find . -type d -exec chmod g+s {} +

 # 4. Apply Default ACLs (Access Control Lists)
 # This forces all NEW files to automatically get group read/write (664/775)
 # overriding any restrictive defaults hardcoded into older scripts.
 find . -type d -exec setfacl -d -m g::rwx {} +
 find . -type d -exec setfacl -d -m g::rw {} +

 # 5. Restore execute permissions to the Perl scripts so they can run
 find . -name "*.pl" -exec chmod +x {} +
 find . -name "*.cgi" -exec chmod +x {} +