I have the same problem as already describes in this thread - Demux summarize error: Plugin error from demux- 'NoneType' object has no attribute 'strip'.
I checked to see that I did have one too many or too few sequences after looking at the divisibility of total number of sequences by 4.
I have 300 fastq.gz files and I may not be able to investigate one by one. Is there a solution to summarize my demux.qza file ?
Also, I am using dada2 to perform sequence variants. So far it is running okay. Should I expect any errors ?