Taxonomic memory issue

Let's slow down and take a step back here.

2 days ago you reported this:

Okay, so we we initially started with an out-of-memory issue - not too uncommon.

Okay, so this is a completely different error message.

Before we sort out the memory error, let's address the "not a QIIME 2 Artifact" issues.

Can you please run the following, and copy-and-paste the complete error message:

qiime tools validate silva-132-99-nb-classifier.qza

qiime tools validate rep-seqs.qza

In general, you need to provide the entire error message, rather than just cherry-picking what you think might be relevant - more often then not there is a significant amount of context available in the complete error messages, which is why we ask for them.

Keep us posted.

PS - I am about to address the question you have asked about over here: TaxonomicClassifier. One thing I think might present as a confounding issue is that you have mutated your QIIME 2 environment, by installing a random version of scikit-learn in it. If you're using the same env in both of these posts, that might be problematic. I would suggest deleting the env and reinstalling (it should be pretty quick - conda will cache all the packages from the first env you created).