Visual Studio 2010 Could not load file or assembly

Visual Studio build error: :
Error 15 Could not load file or assembly 'file:///C:\Documents and Settings\kumard\My Documents\Visual Studio 2010\Projects\LANSW.LMS\site\References\SwitchIT.DataAccess.dll' or one of its dependencies. Operation is not supported. (Exception from HRESULT: 0x80131515)


  • Right click on each *.dll file in Windows Explorer.
  • Uncheck “Read Only”.
  • Click “Unblock”.

If dll are stored in a network drive, move them locally and re-add your references.


Diganta is an experienced Technical Program Manager with a passion for technology. He has architected and developed software for more than a decade for a broad range of industries. Diganta is a founder of two online IT businesses. He is a certified AWS Solutions Architect, AWS Certified Developer, Professional Scrum Master (PSM I), Professional Scrum Developer (PSD I) and ITIL Certified. He has presented at Microsoft Tech.Ed, Microsoft AppFest and Ark Group Intranet conference in the past. He attends AWS Seattle Official Events and Seattle AWS Architects-Engineers. He likes to help, mentor, and manage software development teams to improve and produce great software.

Tagged with:
Posted in C#, Visual Studio
3 comments on “Visual Studio 2010 Could not load file or assembly
  1. Jens-Peter Giersch says:

    Are you sure that this resolves this issue?

    If I paste a path with “file:///” into the Windows Explorer, I get an error message stating the same: File not found.
    If I remove one of the slashes, everything works fine.
    But how do I tell VS2010 to use the correct path?

  2. I hate to admit it but you were right: Using a local location for the project files solved the problem.

    But I am a bit irritated: Isn’t it possible to put project files to a network drive? Not to helpful if I need to work on different machines…

  3. Andreas says:

    Thanks a lot , You’ve saved me lot’s of time , such an unpredictable solution was…

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.