[SOLVED] Graph Widget displays no data

i’m using openhab2 with mariadb and persistent config. everything works fine till yet.
Now i tried to add a graph widget with follow settings:

Type: Default
oH Item: # Livingroom_Temperature
Period: h

all Informations of Livingroom_Temperature stored in mysql db in table item0021. But Graph Widget didn’t generate a temp-line. I already checked the items-table to verify the tablename and itemname

I can’t find any errors on var/log/openhab2

Whats wrong?

I have some Updates:

i use the jdbc persistent mode in habpabnel and using n3-line-chart mode to show values. it works but i can’t showing legend on y-bar.

do i need to change persistent mode to mysql instead?

i solved this issue with leaving y-bar informations empty.