like my attachment printout
did you deleted install folder?
Can you access the admincp?
An internal server error would be logged in your webserver's log location.
Please can you try to browse to your error logs (see : /var/log/apache2 usually) and paste the final few lines here?
This may help us to narrow down the error for you

(2021-02-06, 12:27 PM)Alhimika Wrote: [ -> ]did you deleted install folder?

miss the last step. Many thanks!