The most recent release appears to have broken the table display. If you go to any of the TCGA cohort workspaces you can see this. For example, in the samples table the participants field is empty, and in the pairs table, the case_sample, control_sample and participants fields are empty. Note that if you download the load files, the foreign key attributes appear in the TSV file.
This is a major GUI bug and should be fixed ASAP.