This is a generic error message displayed on an ASP.Net web page. If the error message further indicates that "..the custom error settings for this application prevents the details of the application error from being viewed remotely.." (as seen below) then follow step #1 below to get additional information about the cause of the error.
Endowment Manager Error
  1. Get the actual error details. Repeat the same steps that generated the error on the actual web server running the Endowment Manager application, or turn off custom errors in the web.config file as shown below:
    <customErrors mode="Off">
  2. Please contact support with these error details.