MediaWiki image uploads: "error creating thumbnail"


My wiki over at has been working fine for years now, including the uploading of images and creation of thumbnails for those images. Out of the blue, since a couple of weeks, thumbnails are no longer created and instead I get an error that states simply: “error creating thumbnail:” (including the colon).

LocalSettings.php snippet which has worked up until recent:
$wgEnableUploads = true;
$wgUseImageMagick = true;
$wgImageMagickConvertCommand = “/usr/bin/convert”;

How does something that has worked for years, suddenly no longer work?
Anyone know a fix?


Edit: SOLVED as per this thread:
All I had to do was add $wgMaxShellMemory = 524288; to LocalSettings.php.