An issue can sometimes be encountered, where case notes are unable to be created against some Note Contact Types.
This is known to currently result from one or more space characters prepended or appended to the Note Contact Type's name.
Please see the following steps to identify and then amend any Note Contact Types affected by this issue.
1. Open Settings.
2. Scroll to the 'Support Coordination' section, and then open the 'Note Contact Types' settings page.
3. Open the first Note Contact Type.
4. Check whether there is a space prepended or appended to the intended name of the Note Contact Type, in the Description field.
5. Edit the Description field so that there is no longer a space before or after the Note Contact Type name, then click 'Save'.
6. Check the remaining Note Contact Types, and repeat correction as required for any others affected.