500 internal error while trying to activate

in the .htaccess file, I removed all the lines that start with

RewriteRule . index.php [L]# BEGIN W3TC Browser Cache

and end with
# END W3TC Browser Cache

Now only my home page works while all the pages give me a 404 error even after deactivating the W3 total cache plugin.
Can you please help me?

Okay, problem resolved but I still haven’t dared to activate the W3 plugin again.
I just changed the whole .htaccess file as below which I got from another support thread.

# BEGIN WordPress
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule . index.php [L]
# END WordPress

For some reason, these lines were there:

RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]

I don’t know what ([_0-9a-zA-Z-]+/) is for.

Can you tell me how to get W3 total cache active on my site without these errors? Is there a problem with the version of WordPress – 4.4.2 or the fact that it is a multisite?