Hi @rwoodland,
Version mismatch will be fixed in the next version release.
The error 2-5 can be caused by other things (e.g. Incompatible products detected) but definitely not because of version mismatch.
Could you please quickly check in the spacedesk Driver Console window -> Diagnostics -> Incompatible Software.
For assistance, please also check the Troubleshooting -> Windows PC (Primary Machine) chapter in the user manual https://forum.spacedesk.netuser-manual/.