# Troubleshooting

## Micro-Manager directory not found

```sh
pymmcore-plus - ERROR - (_discovery.py:256) Could not find a compatible Micro-Manager installation for the device interface required by pymmcore 75.

Discovered installations:

Please run 'mmcore install'.
```

... usually followed, when you call `loadSystemConfiguration()`, by:

```sh
FileNotFoundError: Path does not exist: MMConfig_demo.cfg
```

If you tried to create a `pymmcore_plus.CMMCorePlus` instance and got an error similar to the one above, it means that pymmcore-plus was unable to find a Micro-Manager installation on your system whose device interface version matches your version of `pymmcore`. Please run `mmcore install` to install the latest compatible version of Micro-Manager. You can run `mmcore list` to see which installations were found (and which of them are incompatible).

See the [installation](<https://pymmcore-plus.github.io/pymmcore-plus/install/#installing-micro-manager-device-adapters>) section for more details.

## Incompatible device interface version

```sh
OSError: Line 7: Device,DHub,DemoCamera,DHub
Failed to load device adapter "DemoCamera" from "/Users/user/Library/Application Support/pymmcore-plus/mm/Micro-Manager-74.20260129/libmmgr_dal_DemoCamera" [ Incompatible device interface version (MMCore requires 75; device adapter has 74) ]
```

If you create a `pymmcore_plus.CMMCorePlus` instance and you get an error similar to the one above when trying to load a Micro-Manager configuration file, the device adapters that pymmcore-plus is using were built for a different device interface version than your `pymmcore`. This usually means that `MICROMANAGER_PATH` (or the `mm_path` you passed to `CMMCorePlus`) points to an older (or newer) installation. Either point it at a compatible installation, or **update** your Micro-Manager device adapters (for example by running: `mmcore install`).

See [understanding device interface versions](<https://pymmcore-plus.github.io/pymmcore-plus/install/#understanding-device-interface-versions>) for more details.

## Slow performance

If you are experiencing slow performance with pymmcore-plus, you can profile your code to identify bottlenecks. See the [profiling](<https://pymmcore-plus.github.io/pymmcore-plus/profiling/index.md>) section for more details. If you identify a specific issue, or have a question regarding the interpretation of the profiling results, please [open an issue](<https://github.com/pymmcore-plus/pymmcore-plus/issues/new>) and attach the profiling results if possible.

## Something else?

Turning up the [log level](<https://pymmcore-plus.github.io/pymmcore-plus/guides/logging/index.md>) (`PYMM_LOG_LEVEL=DEBUG`) often shows what pymmcore-plus was doing when things went wrong, and `mmcore logs` shows the log file. If you're still stuck, please [open an issue](<https://github.com/pymmcore-plus/pymmcore-plus/issues/new>) and include the output of `mmcore info`.