Error on page

[dyli795]

I imagine the reasons can be many and varied but sometimes bottom left of the screen, above the taskbar, a page will load with the message "Error on page." It doesn't present a problem usualy except e.g. manipulating E-bay, filling in forms to send and receive information, then I think it is a problem.
What, I wonder can be the most likely cause or causes for this and how might it be remedied?