If you get the following error message in Maxquant:

.Net Core 3.1.100 needs to be installed. Please visit: https://dotnet.microsoft.com/en-us/download/dotnet/3.1 and install the SDK x64.

You can resolve this issue by following these steps:

• Check if .Net Core 3.1.100 or higher is installed. If not, download and install .Net Core.
  Using the link: https://dotnet.microsoft.com/en-us/download/dotnet/3.1

If .Net Core is already installed but the error message is still present, you can resolve this issue by following these steps:

• Open the Startmenu and search for "environment variables". Open "Edit the system environment variables" from the search results. (Administrator right are required to edit these settings)
• The screen System Properties will open -> Open "Environment Variables" under "System Variables", select "path" en click on "edit"
• If the line "C:\Program Files (x86)\dotnet" appears above "C:\Program Files\dotnet", use the "Move Up/Move Down" buttons to rearrange the lines until "C:\Program Files (x86)\dotnet" is positioned below "C:\Program Files\dotnet".
  Important: Do not delete lines.
• Click "Ok" and again on "Ok" to save the settings.
• Now reboot your computer.