Received Critical Error: Error in data of page with controller

[timstuck]

Can you please tell me what this error means and why we received it?  This was copied from the Message Manager.

Error
Message status: critical
Date: 05/16/2016 05:07:24 AM
Number of repetitions: 0
Error: Error in data of page with controller: 'pages/product/category'. Please check for key_value present where key_param was set

[Basara]

Hello.

Try search forum
http://forum.abantecart.com/index.php/topic,4480.msg19580.html#msg19580
http://forum.abantecart.com/index.php/topic,2775.msg11837.html#msg11837
http://forum.abantecart.com/index.php/topic,972.msg3650.html#msg3650