I think the R-HRS bottom crate has a hardware problem, it's a long story. But there's a chance it's due to controls. We plan to upgrade to use the rPI boards today. This can't make it any worse. After that, we may need to struggle some more to find the bad card(s) or crate which is causing this. The GUI freezes because it gets either no information or corrupted information. Granted, the GUI should not freeze, but ultimately it's a hardware problem. Anyway, we're working on it.