Error when trying to use the add-in: "The program can't start because api-ms-win-crt-runtime-I1-1-0.dll is missing..."

You receive the following error message on Windows when trying to use the Excel add-in: The program can't start because api-ms-win-crt-runtime-l1-1-0.dll is missing from your computer. Try reinstalling the program to fix this problem.

This message informs you that a Windows update which is part of the 'Visual C++ Redistributable for Visual Studio 2015 Library' is missing on your computer or failed to install.

Solution

To solve this issue, you need to install all available Windows updates and then update the 'Visual C++ Redistributable for Visual Studio 2015 Library' as explained in the following steps:

1. Install All Windows Updates
   1. Navigate to 'Windows Start > Control Panel > Windows Updates'.
   2. Check for updates.
   3. Install all available updates.
   4. After all updates are installed, restart your computer.
   5. Repeat steps 1. to 4 until no more updates are available.
2. Install Visual C++ Redistributable for Visual Studio 2015
   1. Go to the Visual C++ Redistributable for Visual Studio 2015 page, and click Download:
      
   2. Download vc_redist.x64.exe if you are on a Windows 64-bit system or vc-redist86.exe if you are on a Windows 32-bit system.
      
      
   3. Run vc_redist.x64.exe (Windows 64-bit) or vc_redist.x86.exe (Windows 32-bit) and select Uninstall.
   4. After uninstalling the package, run the same .exe again and choose Install.
      Note: If you are experiencing issues with the installation of the 'Visual C++ 2015 Library', make sure that all libraries prior to that version are also installed on your system. You can find all Visual C++ downloads on this Microsoft Website. 
3. Update the Windows Universal C Runtime Libraries

The Universal C Runtime Library Package can be downloaded and installed either through Windows Update or through the Microsoft Download Center. Click on the below link to obtain the download files for your corresponding Windows system: Update for Universal C Runtime in Windows