Hmm. Not sure why that error is coming up. Block 1 is clearly defined. But Block 3 is not, so that should cause an error. Did you have n3 and d3 leftover in workspace from some previous work? But that doesn't explain why blkbuild thinks Block 1 is not defined. Intead of posting a screenshot, it would be better to post the actual code here, maybe as a comment to your question or edit your question to include the actual code. Also, show the results of
which blkbuild -all
