Thank you very much for the report and I am very sorry to hear about this!
So far we did not receive any similar reports like this one. Since the crash happens on Rhino side, I'm wondering if you could forward the relevant info to Rhino support and see what they think about it?
As you are using Rhino 7, you'll need the Grasshopper-Archicad 25 INT 4010-1.0 add-on.
We have 2 add-ons for AC25 (only 1 can be installed at a time, so you need to uninstall your current add-on). One supports Rhino 5 & 6, and the newer one supports Rhino 6 & 7. We kept the old one around for now, as we needed to drop support for Rhino 5 with the new add-on.
I doubt it’s Rhino's fault. I’ve used previous (Grasshopper-ARCHICAD_Connection-25-INT-3003-1.1) release with Rhino 7. Following Rhino support suggestions, I’ve copied ArchiCADConnection.gha from the Rhino 6 folder to Rhino 7 and that worked perfectly. Now, with the official release( Grasshopper-ARCHICAD_Connection-25-INT-4010-1.0) compatible with Rhino 7 I have that error. Sick