Hi @Tinaye,
The error message suggests that you have an issue with metadata:
Metadata does not contain any columns that satisfy this visualizer’s requirements.
And that the data isn't categorical:
There must be at least one metadata column that contains categorical data, isn’t empty, doesn’t consist of unique values, and doesn’t consist of exactly one value.
This could be one of a few problems. First, please check out this question and answer, which addressed a similar issue.
First, if you've coded your categorical data as numbers (i.e. 1=female, 2=male), perhaps consider either re-coding as words or setting a datatype row in the mapping file (see this documentation for details).
Second, if you have a small number of samples, you may simply not have enough samples to make comparisons. For instance, if you have one sample per treatment group, you can't do any comparisons. There was a discussion about this in the thread linked above, as well as here. It's a larger issue than simply QIIME, but also worth thinking about.
Best,
Justine