Fixing a 500 Internal Server Error Installing a Grav Skeleton on Subdomain Hosted by 1&1

I don’t know if it was installing on a subdomain or a problem with 1&1 (1and1) hosting but I was getting a 500 server error on any page of the Grav Skeleton I uploaded and unzipped there except the front page. This is the error:

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.

This is talked about in the Grav docs but none of those solutions worked for me. What did work was a one-line tweak to the .htaccess in the root of the directory I unzipped the Grav skeleton into. Simply went from this:

## Begin RewriteBase
# If you are getting 404 errors on subpages, you may have to uncomment the RewriteBase entry
# You should change the '/' to your appropriate subfolder. For example if you have
# your Grav install at the root of your site '/' should work, else it might be something
# along the lines of: RewriteBase /<your_sub_folder>
##

# RewriteBase /

## End - RewriteBase

to this:

## Begin RewriteBase
# If you are getting 404 errors on subpages, you may have to uncomment the RewriteBase entry
# You should change the '/' to your appropriate subfolder. For example if you have
# your Grav install at the root of your site '/' should work, else it might be something
# along the lines of: RewriteBase /<your_sub_folder>
##

RewriteBase / # <-------Uncommented this line.

## End - RewriteBase

and all was well. I could browse around all the pages of the skeleton, not just the root page.
Note, the comment above the line I changed is talking about 404s, but I was seeing 500s.

TAGS > 1and1, grav, webdev