Won't create a new line

I’ve made a new line in the Line Bodies. Although, I’m not allowed to implement this body line while creating a new line. This hasn’t been a problem till now. All previously made lines are allowed to be chosen. I restarted the Dorico (4.2), than the computer - nothing changes… Could anybody help solving this problem?
This is a created line:

Welcome to the forum, Martins. Can you attach the project containing this new line body here, so we can take a look?

Sorry, I’m not allowed to uploud the file because it is too big. It is an orchestral score containing just two pages but allready has weight of 62 mb. So I made a lighter project.
Untitled Project 1.dorico (462.5 KB)
The Line Body „Trillnirba“ is not allowed to be used for new lines…

For now I’ve solved this problem by importing svg graphic instead of using glyph from font while creating a repeatable symbol…

I’m afraid there’s no “Trillnirba” line body in the project you’ve attached. Is this perhaps a line body that you’ve created and saved as default but not then used in this new project?

Yess, it is saved as a default line body. Though, unfortunately I can’t create the line from that line body, so I’m not allowed to use it in the project. I make a new body line using a symbol from graphic (Trillnirba 2. Than I created the Trillnirba line successfully, but the program won’t allow me to change it to the line body Trilnirba because (I gess) of it is made from the font which I use for symbols. Perhaps the problem is with my font; allthough, I’ve been using this font all the time… The weirdest thing is that the line body of itself is allowed to be created and looks OK…
Unfortunately, I have no permission to upload the font itself. Thank you in advance for any ideas…
Untitled Project 1.dorico (535.4 KB)

I’m afraid I’m still not sure what the problem is. In your new project, there is a line body called Trillnirba 2, and I find that I am able to choose that in the Library > Lines dialog for either a new line or any existing one, e.g. the line you have created called New.

Thank you for reply! Yess, for shore, you are able to use the line body Trilnirba 2, because the symbol for this body line is made from graphic. Although I have made the body line Thrilnirba (not Trillnirba 2) that you perhaps aren’t able to see and use, are you? So, I have made Trilnirba line body, but Im not able to use it as a real line (this is whay I’ve prepared another working line body Trilnirba 2 that works) - when I choose the line body Trilnirba (which I have prepared on my computer) nothing hapens, it just wont change the line. Maybe this problem is not so relevant because I’m still able to make a body line from the symbol chosen as a grafic element (while applying a glyph from font doesnt work…). I can’t substantiate my problem cause you are not able to see the non functioning line body :).

I can look into this further if you send me the font and your userlibrary.xml file, which should contain the line body definition. You can send these things to me privately via email to d dot spreadbury at steinberg dot de.