When is a license rendered invalid by the licensee?

[merkaba22]

I am looking for the standards/cases that establish the criteria for establishing, if ever, when violating the terms of a patent license/settlement agreement render the license invalid or unenforceable, etc.

In the instance I am reviewing, at least, the licensor/manufacturer adapted the licensed technology (for a specific licensed product A) to new products, B and C, not covered in the agreement without notice or negotiation to the licensee while paying royalties as if there had been such an agreement;

Failed to cure within 30 days of (several) notice(s) as per the settlement over the course of a year:

Ignores communication redirected by the manufacturer's attorney named in the settlement to a contact within the manufacturer--