The gateway-load plugin can show the all the matching items in a rule, and from there you can derive and identify the rules with potential invalid targets.
You can use the direcotryStats Category of the gateway load plugin. Refer to the sample xml below:
The resulting dataview will look something like:|
Some rules like FKM on the triggerDetails column could report 0 matching items and this could be normal and expected when there is no error key matching it in the log file.