I hope this is the right place for this bug report. I tried to perform a simple meta-analysis on compose.neurosynth.org using New Project -> Search & Curate / Simple Workflow -> Import some studies from Neurostore -> Move to Extraction Phase -> Start Extraction. At this last step an error popup appears saying "There was an error":

According to the developer console, the problem might be related to a CORS policy issue while requesting data from Neurostore:

I was unable to proceed from here.