Linux Azure Function upgrading from dotnet 6 to dotnet 7 - Did not find any initialized language workers - error

If you created a Linux Azure Function using dotnet 6, and then upgraded the dotnet code to dotnet 7, you may see the following error when you deploy it:

Did not find any initialized language workers

This is because the container the function is running in, is still using the dotnet 6 runtime.

You need to execute the following in the Az Cli, swapping out the values for your function app:

az functionapp config set \
 -g <resource_group> \
 -n <function_app_name> \
 --subscription <subscription_id> \
 --linux-fx-version "DOTNET-ISOLATED|7.0"

This will update the function app to use the dotnet 7 runtime.

NOTE The Azure Function app should restart by itself, but if not, you can restart it from the portal.