Okay. Issue only affects 11.3-U5.

We have regular problems with users inputting invalid auxiliary parameters, breaking the SMB service, and filing bug tickets. It's unclear whether there will be an 11.3-U6, but I backported validation from 12.0-stable. Enclosing parameters in quotes will not be supported. Validation will remain bare-bones, we just pass along parameters to pyparam (lib/param in samba).

Auxiliary parameters in general are a grey-area in terms of what's supported. We generally won't do something that will impact them in a U-release, but behavior and what's permitted may change radically in major version changes. Bug reports and issues with auxiliary parameters will also generally receive a low priority.

The big picture of our path forward is to reduce user's reliance on them to do things. This will be in part achieved by adding configuration presets to SMB shares. If you have a particular item that must work in your environment, then I recommend that you file a feature request to expose it.

11.3 PR: https://github.com/freenas/freenas/pull/5943

Please attach a debug from the affected system and fill out the version information in this form.

i noticed this behaviour on FreeNAS-11.3-U5. 

After your comment i tested on TrueNAS-12.1-MASTER-20201... and the issue seems gone.

But i noticed that entered parameters are not vaildated against smb.conf syntax. so you can add something like "asd =sdgkb" and no error comes up.

Empty lines and comments are permitted in the DB (and show in the GUI), but they are not added to the actual service configuration due to limitations of the configuration backend we are using for samba.