New install doesn't give login, also 500 internal error

I’ve been reading through these installation issue posts and have not been able to solve my own problem, even though it sounds the same. I have installed Sitecake in a subdomain because I have a Wordpress site, and I only want to use Sitecake on a couple of pages. I installed the files, made sure permissions on the subdomain dir were set to 775, and I have a test file with Sitecake tags, but no login appears. My PHP version was just updated yesterday to 7.2. I don’t have an error log for Sitecake because it hasn’t even accessed it yet. I tried to check, but I get a 500 error on that, too. I don’t know what else to try. My test page is there: I just can’t get the login to come up.

Problem was with file permissions.

My problem was file permissions. Although I thought I had made sure they were all 755 (dir) and 644 (files), apparently they were not. it is working now.