I'm one of the people working on tedana.

What version of tedana are you using. AFNI should use whatever version of tedana is in your path so, if you type

tedana --version

that should tell you.

The most common reason this happens is if too many components are retained during the PCA dimensionality reduction step. As part of the tedana output, you should have a file called tedana_[date/time].tsv. There should be a section that looks like:

2022-11-22T15:17:19	pca.tedpca      	INFO    	Computing PCA of optimally combined multi-echo data with selection criteria: aic
2022-11-22T15:17:27	pca.tedpca      	INFO    	Optimal number of components based on different criteria:
2022-11-22T15:17:27	pca.tedpca      	INFO    	AIC: 71 | KIC: 62 | MDL: 42 | 90% varexp: 128 | 95% varexp: 162
2022-11-22T15:17:27	pca.tedpca      	INFO    	Explained variance based on different criteria:
2022-11-22T15:17:27	pca.tedpca      	INFO    	AIC: 0.802% | KIC: 0.784% | MDL: 0.735% | 90% varexp: 0.9% | 95% varexp: 0.95%

For this dataset, I am using the AIC selection criterion which gives me 71 components with an explained variance of 80.2%. (This specific dataset has 200 volumes total). What numbers are you seeing here? You can either cut & paste this section, or attach your output file here.

Dan