Failed to evaluate alert rule

I have encountered a problem in my Grafana instance logs, which is installed using Helm Chart:

ogger=ngalert rule_uid=YT0je_S4k org_id=1 version=1 attempt=0 now=2024-01-29T10:41:30Z t=2024-01-29T10:41:30.005503023Z level=error msg="failed to evaluate alert rule" results="[{Instance: State:Error Error:failed to execute conditions: failed to build query 'A': can not get data source by uid, uid is empty EvaluatedAt:2024-01-29 10:41:30 +0000 UTC EvaluationDuration:5.496748ms EvaluationString: Values:map[]}]" duration=96.685┬Ás

Does anyone have an idea about how to resolve it?