Mysidia After Installation Gets Http500 error

[Trua]

Hello!
I've been trying to install Mysidia 1.3.4 on byethost (https://byet.host/), and I've been following all the steps and reached the end of the installment process (the yellow pages) but then after when I try to access my website and the admin page (http://mysidiatestingii.byethost5.com/index.php , http://www.mysidiatestingii.byethost5.com/admincp/index), I get an error that says, something like this:

mysidiatestingii.byethost5.com is currently unable to handle this request.
HTTP ERROR 500

Sorry if this is unclear, I'd be really grateful if someone could help me and let me find out what I'm doing wrong, thanks!