Three States, Two Partial Year Residencies

I was a California resident going to graduate school in New York (and earning income there) for the first half of the year, and then moved permanently to Massachusetts (and established residency) for the second half of the year.  I filled out a NY nonresident tax form and a MA partial-year resident tax form with no issues.  When I try to claim the credit for income tax paid to NY on the CA income tax form (which was earned while I was a CA resident), I get an error that says "CA nonresidents cannot claim other state tax credit paid to this state." (NY).  Is this a legit error flag (i.e. I can't actually claim credit for the tax paid to NY), or is this an "undocumented feature" in TT?