No Graphs / ERROR: Legend too long

Hello. Running observium i do not get graphs for storage, memory.
Pressing the rrd command button shows:

Performance & Output
RRDTool Output: ERROR: Legend too long
Total time: 0.013 | RRDtool time: 0.013s

RRDTool Command
rrdtool graph /tmp/aIc2MdMvSyYFvx08.png --alt-autoscale --rigid --start 1426089278 --end 1426175678 --width 1700 --height 300 -c BACK#EEEEEE00 -c SHADEA#EEEEEE00 -c SHADEB#EEEEEE00 -c FONT#000000 -c CANVAS#FFFFFF00 -c GRID#a5a5a5 -c MGRID#FF9999 -c FRAME#5e5e5e -c ARROW#5e5e5e -R normal --font LEGEND:8:'DejaVuSansMono' --font AXIS:7:'DejaVuSansMono' --font-render-mode normal -E COMMENT:' Size Used %used
l'
RRDTool Files Used
No RRD information returned. This may be because the graph module doesn't yet return this data.