In order to replicate the issue, you need to execute it first resulting in the Metanode in question, containing the Document Viewer node, to be in idle state (not quite certain why that is happening in the first place).
After you mentioned it, I realized that this issue is related to ‘Java Heap Space’. Even if I solve this problem, I’m still facing the ‘undefined’ issue. I’m not sure if I have unnecessary nodes or if I’ve placed the nodes in the wrong location. Frankly, I don’t understand.
After making the last few corrections, I’ll upload the workflow again: final2.knwf (59.6 KB)