ReSharper 8.x does not work in Visual Studio 2010 after installation

After successful ReSharper 8.x installation:

• all ReSharper menu items in VS top menu are disabled;
• there is no Error Stripe near vertical scroll bar;
• No IntelliSense;
• there are no ReSharper highlightings/quickfixes/context actions in Text Editor;
• ReSharper items are missing in contextual menu;
• When you try to clear ReSharper caches, it says "Clear Cache is applicable when solution exists only. Open a solution first.", but the solution is open.

Possible reason:

It might be related to older version of Nuget Package Manager installed to Visual Studio 2010. 

Solution: 

Open Tools | Extension Manager | Updates | Check updates for Nuget Package Manager | Install the latest one