Site moved to new server - Error 500 I inherited a site running craft and I was asked to move it to my server to host it. The other developer zipped the files and made a database dump for me.
Usually, when I move a site, they have Cpanel access, so I just move and it works with a few tweaks, but they didn't have Cpanel and I am in over my head.
I Know I haven't provided a lot to go on, as I don't know what you need to help me. What is a common thing overlooked? I can post error messages if it helps. The main one I get is the following:
[15-Sep-2020 13:22:01 UTC] PHP Warning:  Use of undefined constant _DIR_ - assumed '_DIR_' (this will throw an Error in a future version of PHP) in /home/client/public_html/index.php on line 7

[15-Sep-2020 13:22:01 UTC] PHP Warning:  require_once(./home/client//vendor/autoload.php): failed to open stream: No such file or directory in /home/client/public_html/index.php on line 11

[15-Sep-2020 13:22:01 UTC] PHP Fatal error:  require_once(): Failed opening required './home/client//vendor/autoload.php' (include_path='.:/opt/cpanel/ea-php74/root/usr/share/pear') in /home/client/public_html/index.php on line 11
The main issue is that the require_once CRAFT_VENDOR_PATH.'/autoload.php'; fails.
This is because the DIR constant, used to compute the value of CRAFT_BASE_PATH and CRAFT_VENDOR_PATH is undefined.
Try to define the value of the DIR constant so that CRAFT_VENDOR_PATH points to the vendor directory in your Craft project (it hard to help you further without knowing your directory structure).
Once this is done, as Jamie mentions, you must use composer to install Craft dependencies.
Did you make any changes to the index.php file of is it just like it was in the archive you received from the other dev?