I seem to have a problem installing Moodle 3.4. I successfully made it through the first couple of steps of the install but when I get past where it checks the PHP "variables" it gives me an error 500 and then shows "Site is Upgrading...". Afterwards, it moves on to the next step which is plugin installation. Plugin installation is successful and it moves on to the next step, creating the admin account. I enter in my information, as shown in the video, and click continue. Then, it goes right back to that page and fails to create the user. That page also shows the undefined popup, which is also shown the the video below. Any ideas as to what the problem is?
Screen Recording (since I couldn't upload due to being too big):