Can't open a view's design in SSMS

Because you are using a newer version of SQL Server than SSMS, I recommend you install a SSMS of same version or later than the SQL Server. There is no guarantee that an older version of SSMS will work on a newer SQL Server, but the opposite should work. SSMS should be backward compatible but no guarantee to be future compatible.

I know this answer is not what you want to hear but like stated in How do I ask a good question?:

Keep an open mind

The answer to your question may not always be the one you wanted, but that doesn’t mean it is wrong. A conclusive answer isn’t always possible. When in doubt, ask people to cite their sources, or to explain how/where they learned something. Even if we don’t agree with you, or tell you exactly what you wanted to hear, remember: we’re just trying to help.