Studio debugger since 2018.1.1

Hello,

Last weekend we've updated our Caché version to 

I'm using Studio to develop. I've been using the built-in debugger and it has been working nicely. But now, since the upgrade, I'm getting this error when trying to debug any routine or class method:

Executing ##class(Blue.App.Handler.Adsolut).TestConnection()
<COMMAND>zDebugStub+30^%Debugger.System.1

This is the code for the classmethod I got the error on;

Class Blue.App.Handler.Adsolut Extends %RegisteredObject
{
ClassMethod TestConnection()
{
  w "ok"
  q
}
}

This is my Studio version information;

Cache' Studio Client  2018.1.1 Build 312
Server Cache for Windows (x86-64) 2018.1.1 (Build 312U)

Does anyone know what's wrong?