title: SSIS --The expression was evaluated, but cannot be set on the property
body: <p>I have package that I have been testing for the last 8 months. <br>Today when I deployed the package on the client machine, it gave the following error:</p>
  
  <blockquote>
    <p>MainContainer:Error: The result of the expression
    "@[$Project::FilePath]+ @[System::PackageName]+".xml"" on property
    "\Package.Properties[CheckpointFileName]" cannot be written to the
    property. The expression was evaluated, but cannot be set on the
    property.</p>
  </blockquote>
  
  <p>@[$Project::FilePath] contains the file path. In this case the value is: C:\Verfication_Reports\</p>
  
  <p>@[System::PackageName]:MainContainer</p>
  
  <p>The package executes successfully but it generates the above error in the SSISDB. This property contains the path of checkpoint file. Please help. </p>