The company advises users to migrate to a supported successor such as .NET Core 3.1 or .NET 5, or face potential security issues. Credit: Thinkstock Microsoft will end support of the .NET Core 2.1 open source development platform on August 21, 2021, which could raise security concerns for those running the platform beyond that date. Beginning September 2021, security updates will be issued for .NET Core 3.1 and .NET 5 but not .NET Core 2.1. “This means that if a computer has .NET Core 2.1 installed, it may be potentially unsecure,” Microsoft said in a bulletin posted March 4. “Additionally, if you run into any issue and need technical support, we may not be able to help you.” The company announced there will be no more updates, including security fixes, or technical support for .NET Core 2.1. While applications using .NET Core 2.1 will continue to run, there could be security issues. Microsoft advises users to update to a supported successor, such as .NET Core 3.1 or .NET 5. Supported versions can be found on dotnet.microsoft.com. Released in May 2018, .NET Core 2.1 has been a long-term support (LTS) release, supported for three years or one year after the next LTS release. .NET 5 arrived in November, as part of Microsoft’s efforts to unify its .NET technologies. A first preview of .NET 6 was published last month, with the production version due in November. Microsoft .NETLibraries and FrameworksSoftware Development