Unload all your projects. Click properties on each project and upgrade to .NET6. Then in your client and server projects, note and remove the references projects to upgrade those projects Nuget packages. Then re-add those projects and you're back in business.
Unload all your projects. Click properties on each project and upgrade to .NET6. Then in your client and server projects, note and remove the references projects to upgrade those projects Nuget packages. Then re-add those projects and you're back in business.