What does the "Cache refresh not detected" warning in the backend mean and how do I resolve it?

It means the weather data has not been downloaded from the National Weather Service. You can click the "Refresh Cache" button in the backend to update the cache immediately, however, you probably need to modify your global settings to keep it updated on a regular basis. If you are not running a cron job, select the "Foreground cache refresh" option. Then set the alert cache time out to 10 (minutes), and the forecast and observation caches to 60.

I've just suddenly started having this issue today after months of this thing working flawlessly. In the configuration area I see:
Fatal error: Call to a member function on a non-object in /home/newriver/public_html/components/com_zweather/zweather.class.php on line 831
It won't refresh, won't update. On the front side the module tells me the same thing, and stops the rest of my site from loading, so I've been forced to shut down the module for now.

Could there have been some change at the NWS that is impacting this?

I am facing same problem after installing 6.0.2 in joomla 1.5. When I access Z Weather component from component menu under admin login it displays

Cache refresh not detected

Warning: Parameter 1 to DOMIT_Parser::processingInstructionElement() expected to be a reference, value given in C:\Sarathi\xampp\htdocs\Joomla\libraries\domit\xml_saxy_parser.php on line 739

Warning: Parameter 1 to DOMIT_Parser::startElement() expected to be a reference, value given in C:\Sarathi\xampp\htdocs\Joomla\libraries\domit\xml_saxy_shared.php on line 261
etc.,


I don't understand the replies posted here. please help me to get out of this.

Have you tried clicking the cache refresh button? The warnings should disappear if you set the error reporting to none or system default in the global settings.