Jan Mulkens explains some of those “unresolved reference” warnings in SQL Server Data Tools database projects:
if you’re developing databases in SSDT, like you should, you’re probably getting a lot of build warnings.
One of the warnings you’ll see the most often is the “unresolved reference”.
Usually you solve these by adding either the master, the msdb or some application database as a database reference.
This post is about a warning you might get when out of habit (or, if like me, you didn’t know any better yet) you’re using old system views like sys.sysprocesses. You expect it to work but it simply doesn’t…
Worth reading the whole thing, as well as keeping up-to-date with your DMV and system view usage.