Chart generation failed: null

Yesterday I run into that problem. Only on of my around 100 items causes that problem by creating a graph. All other items create proper graphs. For all the items, the config is the same. But one causes that problem.

My config:
OH 2.5.12 on Win10


// Items stored in rrd4j-persistance
Group gRRD4J

Number  DE000DK1A408_Wert   "Deka Spezial [%.2f €]"                     (gMAPDB, gRRD4J, gFonds, gG2Fonds)
Number  LU0058908533_Wert   "JPM India [%.2f €]"                        (gMAPDB, gRRD4J, gFonds, gG1Fonds)

Membership of gFonds and gG2Fonds is used to show the right items in the graphs.
Membership of gMAPDB is used to restoreonstartup
Membership of gRRD4J is used for graph persistense

Persistence config:

// persistence strategies have a name and a definition and are referred to in the "Items" section
Strategies {
	everyMinute		: "0 * * * * ?"
	everyHour   	: "0 0 * * * ?"
	everyDay    	: "0 0 0 * * ?"

	// if no strategy is specified for an item entry below, the default list will be used
	default = everyChange

// Each line in this section defines for which item(s) which strategy(ies) should be applied.
// You can list single items, use "*" for all items or "groupitem*" for all members of a group
// item (excl. the group item itself).
Items {
	// To persist all items once a day & on every change & restore them from db at startup,
	// UNcomment the next line
	// * : strategy = everyChange, everyDay, restoreOnStartup

	gRRD4J* : strategy = everyMinute

I checked this for both Items:
curl -X GET --header “Accept: application/json” “http://ip-address192.168.2.169:8080/rest/persistence/items/itemname

Both gives me an json.array with values. This tells me, the data are there

give me the error “Chart generation failed: null” on the one item, on all others it is working.

I tried to delete the .rrd file after stopping OH. A new one was created, but this does not fix the problem.

As said, this happen only on one item. Everything else is working perfect.

Which one of those two Items does work?

I’m curious if you have any other Items that do chart with Euro symbol in the label.


not working

I have around 20 of them, all the same definition, only one gives me no graph. Totally strange.