So, I've installed WHMCS many, many times, but this time it's throwing a fit. I find this particularly strange since I've had WHMCS running on this box before as well. I downloaded a fresh copy of 7.7.1 today, uploaded it to the server, set the permissions with chown -R www-data:www-data /path/to/whmcs (obviously the path is obfuscated, I used the actual one in the command), yet I get the error that the configuration file is not writable.
I've tried just switching it to chmod 777, that didn't work either, I also tried 755. Nothing has worked thus far.
This is what the LS output is, you can clearly see that www-data owns the directory and all files inside of it:
total 2716
drwxr-xr-x 19 www-data www-data 4096 Apr 6 23:01 .
drwxr-xr-x 30 root root 4096 Apr 6 22:53 ..
drwxr-xr-x 5 www-data www-data 4096 Apr 6 22:56 admin
-rwxr-xr-x 1 www-data www-data 62251 Apr 6 22:56 affiliates.php
-rwxr-xr-x 1 www-data www-data 1878 Apr 6 22:56 *
-rwxr-xr-x 1 www-data www-data 40784 Apr 6 22:56 announcements.php
-rwxr-xr-x 1 www-data www-data 6953 Apr 6 22:56 announcementsrss.php
drwxr-xr-x 7 www-data www-data 4096 Apr 6 22:56 assets
drwxr-xr-x 2 www-data www-data 4096 Apr 6 22:56 attachments
-rwxr-xr-x 1 www-data www-data 13911 Apr 6 22:56 banned.php
-rwxr-xr-x 1 www-data www-data 579253 Apr 6 22:56 cart.php
-rwxr-xr-x 1 www-data www-data 769224 Apr 6 22:56 clientarea.php
-rwxr-xr-x 1 www-data www-data 0 Apr 6 22:56 configuration.php.new
-rwxr-xr-x 1 www-data www-data 70311 Apr 6 22:56 configuressl.php
-rwxr-xr-x 1 www-data www-data 33161 Apr 6 22:56 contact.php
-rwxr-xr-x 1 www-data www-data 68840 Apr 6 22:56 creditcard.php
drwxr-xr-x 2 www-data www-data 4096 Apr 6 22:56 crons
-rwxr-xr-x 1 www-data www-data 1509 Apr 6 22:56 dist.loghandler.php
-rwxr-xr-x 1 www-data www-data 81975 Apr 6 22:56 dl.php
-rwxr-xr-x 1 www-data www-data 40610 Apr 6 22:56 dologin.php
-rwxr-xr-x 1 www-data www-data 19070 Apr 6 22:56 domainchecker.php
drwxr-xr-x 2 www-data www-data 4096 Apr 6 22:56 downloads
-rwxr-xr-x 1 www-data www-data 47397 Apr 6 22:56 downloads.php
drwxr-xr-x 2 www-data www-data 4096 Apr 6 22:56 feeds
drwxr-xr-x 4 www-data www-data 4096 Apr 6 22:56 includes
-rwxr-xr-x 1 www-data www-data 11937 Apr 6 22:56 index.php
-rwxr-xr-x 1 www-data www-data 67422 Apr 6 22:56 init.php
drwxr-xr-x 5 www-data www-data 4096 Apr 6 22:56 install
-rwxr-xr-x 1 www-data www-data 116025 Apr 6 22:56 knowledgebase.php
drwxr-xr-x 2 www-data www-data 4096 Apr 6 22:56 lang
-rwxr-xr-x 1 www-data www-data 8768 Apr 6 22:56 link.php
-rwxr-xr-x 1 www-data www-data 16480 Apr 6 22:56 login.php
-rwxr-xr-x 1 www-data www-data 16099 Apr 6 22:56 logout.php
drwxr-xr-x 13 www-data www-data 4096 Apr 6 22:56 modules
-rwxr-xr-x 1 www-data www-data 30235 Apr 6 22:56 networkissues.php
-rwxr-xr-x 1 www-data www-data 11857 Apr 6 22:56 networkissuesrss.php
drwxr-xr-x 2 www-data www-data 4096 Apr 6 22:56 oauth
drwxr-xr-x 2 www-data www-data 4096 Apr 6 22:56 pipe
-rwxr-xr-x 1 www-data www-data 18462 Apr 6 22:56 pwreset.php
-rwxr-xr-x 1 www-data www-data 47718 Apr 6 22:56 register.php
drwxr-xr-x 8 www-data www-data 4096 Apr 6 22:56 resources
-rwxr-xr-x 1 www-data www-data 29161 Apr 6 22:56 serverstatus.php
drwxr-xr-x 2 www-data www-data 4096 Apr 6 22:56 status
-rwxr-xr-x 1 www-data www-data 77420 Apr 6 22:56 submitticket.php
-rwxr-xr-x 1 www-data www-data 44849 Apr 6 22:56 supporttickets.php
drwxr-xr-x 4 www-data www-data 4096 Apr 6 22:56 templates
drwxr-xr-x 2 www-data www-data 4096 Apr 6 22:56 templates_c
-rwxr-xr-x 1 www-data www-data 7512 Apr 6 22:56 unsubscribe.php
-rwxr-xr-x 1 www-data www-data 81586 Apr 6 22:56 upgrade.php
drwxr-xr-x 52 www-data www-data 4096 Apr 6 22:57 vendor
-rwxr-xr-x 1 www-data www-data 14887 Apr 6 22:56 viewemail.php
-rwxr-xr-x 1 www-data www-data 36378 Apr 6 22:56 viewinvoice.php
-rwxr-xr-x 1 www-data www-data 51264 Apr 6 22:56 viewquote.php
-rwxr-xr-x 1 www-data www-data 94502 Apr 6 22:56 viewticket.php
-rwxr-xr-x 1 www-data www-data 16436 Apr 6 22:56 whois.php
The permissions for the folder overall are also set to www-data:
drwxr-xr-x 19 www-data www-data 4096 Apr 6 23:01 obfuscated.obfuscated.com
I'm running nGinx with PHP 7.2, all up to date as well. There are no errors in the nginx error.log either.
I'm super confused, any help would be appreciated.