Internal Server Error 500 because of .htaccess

I just set up NC 15.0.5 on a rented webspace at, where I already had a wordpress site running. I moved the wordpress installation with FTP to /wordpress/ and redirected my domain to point there. NC got its own subdomain pointing to /nextcloud/ on the webspace.
After unzipping NC on the webspace, Firefox instantly threw an Error 500 at me when I browsed to I read that this could be a problem of a .htaccess file, so for testing purposes I simply deleted .htaccess from /nextcloud/ and suddenly it worked. I guess it is not very smart to leave it like that, so how do I have to edit the .htaccess to get it to work?

thanks in advance!

*edit: I got a little closer to a solution. NC seems to work fine if I just remove the line “Options -Indexes” down at the bottom of .htaccess. Still gives me a warning about the bad hash of said .htaccess obviously, 'cause I edited it.
What does this line do? Is it a security risk to run without it?