Remove the Mark of the Web: Visual Studio 2019 Build Error

I’m getting ready to start another semester of teaching Windows Form Application programming at Buffalo State College and over the summer our installation of Visual Studio has been upgraded to 2019 (I taught using 2015 last semester). While there’s not a lot of changes, one thing that threw me off is this “remove the mark of the web” build error:

Error Couldn't process file frmMain.resx due to its being in the Internet or Restricted zone or having the mark of the web on the file. Remove the mark of the web if you want to process these files. FinancialCalculations
There are a lot of proposed solutions out there, but this is what worked for me:

  1. Unblock the file in Windows ExplorerClose the project in Visual Studio 2019
  2. Find the file in Windows Explorer
  3. Right click and go to Properties
  4. On the General tab, look at the bottom where it says “This file came from another computer and might be blocked to help protect this computer.” and click the Unblock checkbox
  5. Click OK, then re-open the project and try building it again

Now you should be able to build your Visual Studio 2019 project without being stopped by this “remove the mark of the web” error.

I hope this helps you, too and good luck to all of the students starting or returning this semester!

  • Edward Beck
    Posted February 26, 2020 8:10 am 0Likes

    Thanks that was a great help!

  • Paku
    Posted August 3, 2020 7:54 pm 0Likes

    Thanks heaps!

    Posted August 14, 2020 2:59 pm 0Likes

    Thanks, this problem drove me nuts this morning at work, thansk for the solution, by the way it is not documented anywhere

  • Jack Eisenfeld
    Posted August 27, 2020 3:37 pm 0Likes

    I am receiving the “mark of the web” error but, when I go to Properties of the RESX file, there is no option to unblock the file. Is there a setting or something in Windows 10 that will cause Windows to give me this option?

    • Eric Nagel
      Posted August 30, 2020 10:44 am 0Likes

      Jack and I emailed back and forth and he discovered, “I had the Form1.resx file in a Dropbox folder. When I copied it to my hard drive (C:), the Unblock option appeared.”

      Maybe that will help someone.

      • Sharif Zaman
        Posted July 10, 2021 1:02 pm 0Likes

        Yes it did help!

    • Sam
      Posted March 21, 2022 7:34 pm 0Likes

      Thanks I had to do this to every file.

    Posted September 17, 2020 12:02 am 0Likes

    if you don’t see the unblock attribute you follow this

  • Natalie
    Posted October 1, 2020 4:57 pm 0Likes

    THANK YOU for that insight! My computer died, the program worked on that one. When I got my new computer, downloaded the file and tried to run it, I got this error. I tried many things until I came across this. THANK YOU! (Florida adult learner student learning C# via VS2019 Windows Form App).

  • Sharif Zaman
    Posted July 10, 2021 1:01 pm 0Likes

    Thanks so much for taking the time to post how to handle this error. I also did not see the check box as it was in my OneDrive. Once I moved it to my desktop, the Security: unblock checkbox appeared. Once unblocked, the checkbox option is removed. I then could put back in the OneDrive and it was still OK. Thanks Again.

  • Bill Gunn
    Posted August 6, 2021 8:28 pm 0Likes

    MANY thanks Eric – simplest and best solution.
    I have been marking student assessments – and come across this error on about half of the submissions. And yes – it has been driving me mad !
    greatly appreciated

  • Aarti
    Posted October 23, 2021 5:10 am 0Likes

    Thank You, for this post.

  • Dave
    Posted March 27, 2022 4:25 pm 0Likes

    Thanks! So nice to find a solution online that is easy to follow and worked!

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