MangeshANSYS
Ansys Employee

yes, both of them should be same version i.e.
both (Ansys Mechanical and Ansys EDT) 2024 R2
or both (Ansys Mechanical and Ansys EDT)2024 R1
or both (Ansys Mechanical and Ansys EDT)2023 R2
etc

if you have say Mechanical 2023 R2 and Ansys EDT 2024 R1, then system coupling will not work