Hi @LauraMason,
Could you please share the precise command that you are using, and the complete error output?
It looks like that earlier discussion may or may not have been resolved…
In my opinion (having run into similar issues myself when migrating data from QIIME1 to QIIME2), the easiest fix may be to just import the representative sequences into QIIME2 and align/build a tree from scratch. But let’s see the error that you are contending with now and strategize from there.
Thanks!