When I launched my Azure Function with PnP Powershell, I encountered an exception: “Could not load file or assembly ‘System.IdentityModel.Tokens.Jwt, Version=6.35.0.0’.” Upon investigation, I discovered that PnP had upgraded to the new assembly, but it was not present on my function host. The host runtime version was displaying as 4.29.1.21919.
A quick search on Google revealed that the GitHub release notes for version 4.30.0 include the latest version of the assembly.
https://github.com/Azure/azure-functions-host/releases
Now, being in Azure Government, we are often left in the dark regarding release schedules. I submitted a ticket explaining my findings, but progress was slow with the representative on when this update would be backported to Azure Government. In an attempt to find a workaround, I created a new Azure Function and confirmed that the runtime had indeed been updated to 4.30.0. However, I had extensively configured my function host and was not keen on redoing all the authentication, among other settings.
The solution? I discovered that upgrading the app plan moves your project to a new host. I upgraded from a B sku to a PV3, ensuring I was transferred to a new host.
After switching back to the B sku, I saw my runtime had updated to 4.30.0.
For those facing a tight deadline to get their systems up and running, this strategy might be a lifesaver. You can preserve all your settings and upgrade your runtime without the need to migrate to a new function.
Azure Testing Site 