This has been answered here: Barostat failure - #2 by hess
Since I notice that you are new here, I’d like to ask you please do not re-post questions repeatedly. Our team is doing their best to answer requests, but it can take a few days. In the meantime, feel free to search the gitlab issues: Issues · GROMACS / GROMACS · GitLab
Cheers,
Szilárd