Can anyone help me?
What do I have to do that I can install Apps on my TrueNAS Scale.
Already tried it via Datasets…
You cannot use in an App the same dataset being shared via SMB.
You should create a dataset for the SMB share, e.g. Pool01-red/myshare and share that instead.
@william Unfortunately this is sometimes necessary. For example, Plex / Jellyfin need media files, and the easiest way to get those onto your NAS is with an SMB share - so you need to have the SMB share accessed by an app.
I cannot remember offhand where the setting is, but you can turn off this warning.
As the error message says, you’re not allowed to share the root dataset like that. Use a child dataset, put your files there and share that with SMB instead.
This has nothing to do with restricted host paths that was a thing a few versions back.