Generally a 500 error is a generic message that could be caused from a number of different things, most often a configuration issue somewhere within the scripting of a site. In the case of WordPress, potentially missing (or incorrect paths to) files when the site was moved.
However, you also mentioned an error pertaining to Installatron which is the automated installation application used on shared hosting plans. Because that is primarily an internal tool on our end, you'll want to reach out to our live support so our hosting team can help investigate what triggered the error and get this corrected. They should be available via phone or live chat to assist you.
Let us know what they find.
CG - GoDaddy | Community Moderator 24/7 support available at x.co/247support