Exception on /api/v1/orchestrations/pipeline-schedules AttributeError: 'NoneType' object has no attribute 'get'

I get this error sometimes when strating meltano ui on a windows machine. The error also happens when I navigate between tabs in the UI. The error is associtated with the following API call in the log

Exception on /api/v1/orchestrations/pipeline-schedules [GET]

Here is the ending bit of the error

  File "C:\development\meltano\src\meltano\core\project_plugins_service.py", line 83, in current_plugins
    self._current_plugins = self.config_service.current_meltano_yml.plugins
  File "C:\development\meltano\src\meltano\core\config_service.py", line 35, in current_meltano_yml
    self._current_meltano_yml = self.project.meltano
  File "C:\development\meltano\src\meltano\core\project.py", line 230, in meltano
    return MeltanoFile.parse(self.project_files.load())
  File "C:\development\meltano\src\meltano\core\project_files.py", line 66, in load
    included_file_contents = self._load_included_files()
  File "C:\development\meltano\src\meltano\core\project_files.py", line 150, in _load_included_files
    for path in self.include_paths:
  File "C:\development\meltano\src\meltano\core\project_files.py", line 59, in include_paths
    include_path_patterns = self.meltano.get("include_paths", [])
AttributeError: 'NoneType' object has no attribute 'get'

It can’t find the attribute get which I think is suppose to be a function of the class ? I also have not been able to determine what the function get is suppose to do. It seems like it is reading the meltano.yaml for the include_paths entries and return all the paths in a list. In the project_files.py there are these back to back function you can see there is a meltano function.

    @property
    def meltano(self):
        """Return the contents of this projects `meltano.yml`."""
        if self._meltano is None:
            with open(self._meltano_file_path) as melt_f:
                self._meltano = yaml.safe_load(melt_f)
        return self._meltano

   @property
    def include_paths(self) -> List[Path]:
        """Return list of paths derived from glob patterns defined in the meltanofile."""
        include_path_patterns = self.meltano.get("include_paths", [])
        return self._resolve_include_paths(include_path_patterns)

In project.py there is a meltano function that returns a MeltanoFile class

    @property
    def meltano(self) -> MeltanoFile:
        """Return a copy of the current meltano config.

        Returns:
            the current meltano config
        """
        with self._meltano_rw_lock.read_lock():
            return MeltanoFile.parse(self.project_files.load())

The MeltanoFile class that is in meltano_file.py has a get_plugins_for_mappings.

[visch]

I can verify that I get this on Meltano with the Uvicorn feature flag enabled. I can’t replicate this on Linux.

[BuzzCutNorman]

@tayloramurphy sure thing. I have python 3.9.12 installed. Meltano was installed using pipx and is meltano, version 2.1.0 . I get the error message even when I start meltano ui in a freshly initialized test project with the default meltano.yml file.

cc @visch @kgpayne @alexmarple