Invalid Simulink object handle error

Question:

I am trying to run my model offline in Simulink and I get the following error:

Error evaluating 'InitFcn' callback of RT-LAB OpComm block (mask). 'TestIntegration1V2_13FPGA/sm_fpga1/opcomm/Out1' Invalid Simulink object handle.

What can I do?

Answer:

This problem is related to a Simulink wire that is not attached or not properly attached to a subsystem at the top level of the model. In the figure below, we can see one wire that is unattached. Remove (or attach properly) this wire, save your model again and run it again. Note that some unattached wires may be difficult to see as is. It is suggested to delete all wires at the top level and do them from scratch. You can automatically create wires between two blocks or two subsystems by clicking on the first block, holding the Ctrl key and clicking on the second block.