500 Internal Server Error after update to 2.19

Since update to 2.19 I get 500 Internal Server Error messages for many pages - unless the option "Inline CSS on specific pages" (admin/config/development/performance/advagg/mod) is activated:

If "*" is set, I get no error messages. If "" is set, only the start page is accessible. If nothing is set there, no page can be reached.

To avoid misunderstandings, the contents of the .htaccess files in the folders "advagg_css" and "advagg_js" follow.

I use PHP 7, Apache 2.4.

Greetings
Frank

advagg_css:

<FilesMatch "^css__[A-Za-z0-9-_]{43}__[A-Za-z0-9-_]{43}__[A-Za-z0-9-_]{43}.css(\.gz)?">
  # No mod_headers
  <IfModule !mod_headers.c>
    # No mod_expires
    <IfModule !mod_expires.c>
      # Use ETags.
      FileETag MTime Size
    </IfModule>
  </IfModule>

  # Use Expires Directive.
  <IfModule mod_expires.c>
    # Do not use ETags.
    FileETag None
    # Enable expirations.
    ExpiresActive On
    # Cache all aggregated css files for 52 weeks after access (A).
    ExpiresDefault A31449600
  </IfModule>

  <IfModule mod_headers.c>
    # Do not use etags for cache validation.
    Header unset ETag
    # Serve correct content type.
    Header set Content-Type text/css
    <IfModule !mod_expires.c>
      # Set a far future Cache-Control header to 52 weeks.
      Header set Cache-Control "max-age=31449600, no-transform, public"
    </IfModule>
    <IfModule mod_expires.c>
      Header append Cache-Control "no-transform, public"
    </IfModule>
  </IfModule>
  ForceType text/css
</FilesMatch>

advagg_js:

<FilesMatch "^js__[A-Za-z0-9-_]{43}__[A-Za-z0-9-_]{43}__[A-Za-z0-9-_]{43}.js(\.gz)?">
  # No mod_headers
  <IfModule !mod_headers.c>
    # No mod_expires
    <IfModule !mod_expires.c>
      # Use ETags.
      FileETag MTime Size
    </IfModule>
  </IfModule>

  # Use Expires Directive.
  <IfModule mod_expires.c>
    # Do not use ETags.
    FileETag None
    # Enable expirations.
    ExpiresActive On
    # Cache all aggregated js files for 52 weeks after access (A).
    ExpiresDefault A31449600
  </IfModule>

  <IfModule mod_headers.c>
    # Do not use etags for cache validation.
    Header unset ETag
    # Serve correct content type.
    Header set Content-Type application/javascript
    <IfModule !mod_expires.c>
      # Set a far future Cache-Control header to 52 weeks.
      Header set Cache-Control "max-age=31449600, no-transform, public"
    </IfModule>
    <IfModule mod_expires.c>
      Header append Cache-Control "no-transform, public"
    </IfModule>
  </IfModule>
  ForceType application/javascript
</FilesMatch>