A subsidiary of Fidelity Investments has filed a lawsuit accusing Broadcom (AVGO) of threatening to cut off access to critical software, potentially causing “massive outages” and trading disruptions unless a court intervenes. Fidelity Technology Group, part of the Boston-based asset manager, alleged in Suffolk County Superior Court filings made public Friday that its operations would face “enormous” harm if Broadcom terminates access to the business-critical software after January 21. The lawsuit states that Fidelity has relied on virtualization software sold by VMware since 2005 to create, host, and manage virtual servers on its physical servers—software that has become central to the firm’s operations over time.