I'm planning to update our SA4500 which is currently running 7.4R9.1 (build 30599) to 8.1r4.1 (b37683) .... and I'm just wondering if it's ok todo in one sweep or do I need to update to Another version first Before 8.1?
We tried upgrading our SA4500 from a 7.x release to 8.1. There were absolutely no problems on the appliance side, but we rolled back the upgrade after clients ran into problems with the Installer Service: The new PulseSecure branded Installer Service wasn't installed correctly, and we ended up with clients that then had both the old Juniper and the new PulseSecure service. Subsequently, upgrade of the Pulse client failed. If you don't use the Installer Service, I think you'll be fine.
I didn't find the time yet to read through newer 8.1 release notes and see if problems in that area have been fixed.