I have installed Joomla, the newest 3.4.3 version in a subdomain on my site to play with. My PHP version is set to 5.3. I used the "SimpleScripts" to install it, and it seems to have installed just fine. I can load the front page, and also the administrator pages.

I have not touched any of the settings or content, but have jumped into trying to setup my first "Hello, World!" module. I've followed the "Creating a simple module" article from Joomla's documentation (copied & pasted all code), however I cannot get the module to install. I tried uploading the zip file, but it says it can't find the XML file (even though it is there...). So, I tried uploading all files into the "tmp" directory & install from directory. Same problem, fusses about the XML file and "Error Please enter a package directory. Unable to find install package".

Next I tried uploading all files into the "modules" directory & telling Joomla to "Discover" the new module. It does appear in my list, but when I select it and tell it to install I get this 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.
When I check my error log, I find this:

20150815T165049: MY_SITE/administrator/index.php
PHP Warning: simplexml_load_file(): /PATH_TO_MY_SITE/modules/mod_helloworld/mod_helloworld.xml:28: parser error : Extra content at the end of the document in /PATH_TO_MY_SITE/libraries/cms/installer/installer.php on line 1942
PHP Warning: simplexml_load_file(): <install> in /PATH_TO_MY_SITE/libraries/cms/installer/installer.php on line 1942
PHP Warning: simplexml_load_file(): ^ in /PATH_TO_MY_SITE
That last line, the path is actually cut short...

Any suggestions? So frustrated that I couldn't even get this to work