This error message appears when you try to upload an image with large dimensions to a MediaWiki website which is configured to use ImageMagick for image conversions.

In order to resolve the issue, you would need to switch the conversion method from ImageMagick to GD Library by changing the following line in your LocalSettings.php file:

$wgUseImageMagick = true;

to

$wgUseImageMagick = false;