ReSharper Ultimate is a set of JetBrains products that includes tools for .NET developers (ReSharper, dotCover, dotTrace, dotMemory, and dotPeek), as well as ReSharper C++ for C++ developers who use Visual Studio.
In late 2014, starting with ReSharper version 9.0, we have changed the development process for ReSharper Ultimate tools so that all of them share a set of common assemblies. This helped drastically reduce the memory footprint of ReSharper Ultimate tools when integrated in Visual Studio, and make Visual Studio much more responsive whenever a combination of these tools was installed.
This change however does have a downside: in order for multiple ReSharper Ultimate tools to share a set of common assemblies, they have to be of exactly the same version. In practical terms, there is only one combination of versions of ReSharper Ultimate tools that you can integrate in a single installation of Visual Studio side-by-side.
This is why whenever you download an installer for any ReSharper Ultimate tool that can be integrated into Visual Studio (ReSharper, ReSharper C++, dotCover, dotTrace or dotMemory), the installer will try to update any other ReSharper Ultimate tools that it detects in your Visual Studio installation.
For example, if you had ReSharper 9 and dotCover 3 installed and you now run a dotTrace 10 installer, the installer will by default try to update ReSharper and dotCover to version 10 so that their versions match the version of dotTrace that you're trying to install. This behaviour might be unwanted if you do have a license to dotTrace 10 but do not have a license to ReSharper 10, or if you simply want to run the latest trial of a ReSharper Ultimate tool.
Unfortunately, there is no guaranteed solution to this problem. However, there are workarounds available to prevent upgrading existing installations of ReSharper Ultimate tools when installing or upgrading another ReSharper Ultimate tool:
- If you are installing dotPeek, dotTrace or dotMemory, make sure to turn off Visual Studio Integration in the installer: although this will limit the functionality available to you to a certain extent, it is not essential for these tools to be integrated in Visual Studio and they can perfectly operate as standalone applications.
- If you are installing ReSharper, ReSharper C++ or dotCover — that is, ReSharper Ultimate tools that require integration with Visual Studio, — the only way to preserve an existing installation is to integrate them into a different version of Visual Studio. For example, if you have an existing installation of ReSharper 9 and dotCover 3 in Visual Studio 2013, and you want to install a recent release of ReSharper C++, consider only integrating ReSharper C++ in Visual Studio 2015.