Thumbnail generation unsuccessful

• DEBUG post_id=26
• DEBUG Found YAPB image
• DEBUG w=500
• ERROR Couldn't save /hsphere/local/home/vanheugten/strik.loba.dk/wp-content/yapb_cache/bart_troje_forfra2.2uw466wp98004sog4sk80osks.bc67xig3hwgk4kog4so80ssks.th.jpeg - Please check cache directory permissions