Deemix just stopped working - "start-build" not found

Deemix has been working well since the new version was posted earlier in the week, but it suddenly stopped this morning. I rebooted the VM and now get the following when I do docker-compose up:

``deemix | [cont-init.d] 10-adduser: exited 0.

deemix | [cont-init.d] 10-fix_folders: executing...

deemix | [cont-init.d] Fixing Folder Permissions

deemix | [cont-init.d] 10-fix_folders: exited 0.

deemix | [cont-init.d] 15-checks: executing...

deemix | [cont-init.d] Testing Access

deemix | [cont-init.d] Container Builddate :

deemix | [cont-init.d] Download Folder Write Access : Success

deemix | [cont-init.d] Config Folder Write Access : Success

deemix | [cont-init.d] Internet Access : Success

deemix | [cont-init.d] 15-checks: exited 0.

deemix | [cont-init.d] 90-custom-folders: executing...

deemix | [cont-init.d] 90-custom-folders: exited 0.

deemix | [cont-init.d] 99-custom-scripts: executing...

deemix | [custom-init] no custom files found exiting...

deemix | [cont-init.d] 99-custom-scripts: exited 0.

deemix | [cont-init.d] done.

deemix | [services.d] starting services

deemix | [services.d] Starting Deemix

deemix | [services.d] done.

deemix | yarn run v1.22.17

deemix | error Command "start-build" not found.

deemix | info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

deemix | [services.d] Starting Deemix

deemix | yarn run v1.22.17``