Troubleshooting “not found” Errors in sh Startup Scripts

## Supported Ubuntu Versions

LarkXR management program deployment is supported on Ubuntu with the following version requirements:

- Server versions `3271` and earlier: Ubuntu `20.04`
- Server versions `3272` and later: Ubuntu `20.04` and `22.04`

## Symptom

After deployment, running the startup script with `sh` returns a `not found` error.

![Example of the sh startup script not found error](https://docs.paraverse.cc/media/202504/e50f5b72a0e84c2bbceb41d7deffe0845947.png)

## Cause

On Ubuntu, the `sh` command usually points to `dash` by default. Some LarkXR startup scripts rely on Bash-specific behavior, so running them with `dash` may cause commands in the script to fail or be reported as not found. [page:6]

## Solution

Change the system default for `sh` from `dash` to `bash`.

### 1. Reconfigure the Default Shell

Open a terminal and run:

```bash
sudo dpkg-reconfigure dash
```

When prompted, select **No**. This changes `/bin/sh` to use Bash instead of Dash. [page:6]

### 2. Verify the Change

Run the following command:

```bash
ls -l /bin/sh
```

If the output shows that `/bin/sh` points to `/bin/bash`, the change was applied successfully. [page:6]

### 3. Run the Startup Script Again

After the shell mapping is updated, run the startup script again and confirm that the `not found` error no longer appears.

## Notes

- Use `ls -l /bin/sh` instead of `ll /bin/sh`, because `ll` may be an alias and is not guaranteed to be available in every environment. [page:6]
- If the script still fails after changing `/bin/sh` to Bash, review the script file format and execution permissions as additional troubleshooting steps. [page:6]