What is the solution for this?
This message occurs when you open a file that was previously saved on a prior version or different computer that had the subassembly content stored in a different directory. The aecc content dir stores that location on the machine, so if it was previously different you will see this message when the subassemblies aren't found in the old location and they are pointed to the location on the current machine.
This is why the message type is Information for these as opposed to warning or error, which would indicate that you may want to change or adjust something(warning) or something isnt working as expected and changes need to be made(error).