Error generating thumbnail

Error creating thumbnail: convert: unable to extend cache `/tmp/magick-gGBXf3HycbFoGaVmi62CAmM6OInES4M0': File too large @ error/cache.c/OpenPixelCache/4117. convert: no images defined `/tmp/transform_bd6308fb7623.jpg' @ error/convert.c/ConvertImageCommand/3229.