Invalid Cast Error with Ros Subscriber

Hello,

I publish and subscribe to a ROS topic in Unity with my own msg and srv. I followed this tutorial: https://github.com/Unity-Technologies/Unity-Robotics-Hub/tree/main/tutorials/ros_unity_integration
Publishing works without issues but the subscriber gets this error: I still receive the message and can print it.

InvalidCastException: Specified cast is not valid.
(wrapper castclass) System.Object.__castclass_with_cache(object,intptr,intptr)
Unity.Robotics.ROSTCPConnector.ROSConnection+<>c__DisplayClass78_0`1[T].<Subscribe>b__0 (Unity.Robotics.ROSTCPConnector.MessageGeneration.Message msg) (at Library/PackageCache/com.unity.robotics.ros-tcp-connector@c27f00c6cf/Runtime/TcpConnector/ROSConnection.cs:194)
Unity.Robotics.ROSTCPConnector.RosTopicState+<>c__DisplayClass56_0.<OnMessageReceived>b__0 (System.Action`1[T] item) (at Library/PackageCache/com.unity.robotics.ros-tcp-connector@c27f00c6cf/Runtime/TcpConnector/RosTopicState.cs:94)
System.Collections.Generic.List`1[T].ForEach (System.Action`1[T] action) (at <c2a97e0383e8404c9fc0ae19d58f57f1>:0)
Unity.Robotics.ROSTCPConnector.RosTopicState.OnMessageReceived (System.Byte[] data) (at Library/PackageCache/com.unity.robotics.ros-tcp-connector@c27f00c6cf/Runtime/TcpConnector/RosTopicState.cs:94)
Unity.Robotics.ROSTCPConnector.ROSConnection.Update () (at Library/PackageCache/com.unity.robotics.ros-tcp-connector@c27f00c6cf/Runtime/TcpConnector/ROSConnection.cs:600)
UnityEngine.Debug:LogException(Exception)
Unity.Robotics.ROSTCPConnector.ROSConnection:Update() (at Library/PackageCache/com.unity.robotics.ros-tcp-connector@c27f00c6cf/Runtime/TcpConnector/ROSConnection.cs:605)


My subscriber:

void Start()
{
//subscribe to topic name and call funtion Print
ROSConnection.GetOrCreateInstance().Subscribe<DigitalTwinMsg>(topicName, Print);
}

//msg is the data from the publisher
void Print(DigitalTwinMsg msg)
{
Debug.Log(msg);
}

 

Yes, other custom messages worked, although I only tried with a single string as a message, apart from the ones from the tutorial.

 

The error was caused by a similar but different .srv file. I deleted it and rebuild my services and messages and its now working fine.