Whenever a user tries to open a synchro .sp file, it launches the Synchro installer and the installer fails with an error 1706. We have tried using the open with function and choosing the correct .exe from program files. We have also tried running synchro in compatibility mode since we are on Windows 10. But none of it has worked.
Try reinstalling Synchro as it may have lost its association with the file format SP.