I've had this same issue for a couple days now trying to figure it out. the above solutions both worked for me. I was able to finally see the error by digging through the Trace table in appinsights and seeing that there was some dependency not met, "azure.monitor" in my case, even though it was in the requirements.txt file. To make matters worse, I was using the yml file that the azure Function App itself built in my repo when i connected it via the Deployment Center in the portal. In that yml file, it doesn't specify the -t parameter for the pip install command. It does gather all the reqs, but it nests it under a venv folder structure that apparently az functions doesn't like. With the -t . parameter, they all get dumped into the root folder and it is able to see them there. I tried the remote-build=true as well to compare, and it does create a directory structure under root as well, but az functions seems to handle that just fine (.python_packages/lib/site-packages/...).