CSS/Image failure, HTML File load failure, randomly happening days after install (no replies)

I've installed Piwik on a Xampp Apache/MySql emulator with no problems, and I'm getting good data, but from some strange reason the day after install I start getting repeated image and CSS access errors.

It's happened twice (I've uninstalled and reinstalled). I also see the following error when I look at the main dashboard:

Failed to load HTML file: Please check your server configuration. You may want to whitelist "*.html" files from the "plugins" directory. The HTTP status code is 500 for URL "plugins/CoreHome/angularjs/menudropdown/menudropdown.html"

When I attempt to access any of the CSS or image files that are showing as broken, I receive the following error:

Server error!

The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there was an error in a CGI script.

If you think this is a server error, please contact the webmaster.

Error 500

localhost
Apache/2.4.9 (Win32) OpenSSL/0.9.8y PHP/5.4.27

For some strange reason this is consistently happening the day after the installation. Right after I install it everything is working fine.

Any ideas for a fix?

Thanks!