I asked in the slack channel of apache nifi. So basically it's all in the stacktrace: org.apache.nifi.controller.FlowController.createPythonBridge(FlowController.java:865. The line on the source code: https://github.com/apache/nifi/blob/rel/nifi-2.0.0-M4/nifi-framework-bundle/nifi-framework/nifi-framework-core/src/main/java/org/apache/nifi/controller/FlowController.java#L865.  Here as a snippet at your convenience:  final File pythonWorkingDirectory = new File(nifiProperties.getProperty(NiFiProperties.PYTHON_WORKING_DIRECTORY)); so because we have a bit of a custom setup we did get all the default python settings as outlined here: https://nifi.apache.org/documentation/nifi-2.0.0-M1/html/administration-guide.html#python_configuration After setting all of those:  nifi.python.command=python3 nifi.python.framework.source.directory=./python/framework nifi.python.extensions.source.directory.default=./python/extensions nifi.python.working.directory=./work/python nifi.python.logs.directory=./logs nifi.python.max.processes.per.extension.type=10 nifi.python.max.processes=100 it then started again and I could import the processor ... View more