Last updated: 06/01/2021


Project administrators have the ability to supplement the wide gamut of information collected by MigrationStudio by attaching additional files to Application, Migration User and Machine records.  For example, an administrator might want to attach a license file to a particular application or upload a UAT sign-off form.

MigrationStudio uses DNS and the server's local storage to upload the file.  If the configuration or environment has changed, users may encounter the error 'Handler not found or execution of the handler failed' when attempting to upload attachments:

This Solution Article discusses the steps that an administrator should take to diagnose and resolve the issue.


The solution may require changes to the MigrationStudio configuration and permissions of the server's filesystem.  A MigrationStudio and Windows account with administrator privileges will be required.

Internet Explorer URL

Check that the Internet Explorer URL matches the value specified in the MigrationStudio configuration:

  • Log into MigrationStudio with an account with administrator privileges.
  • Switch to the Admin view (1) and select Initial Setup (2) from the vertical menu on the left.
  • Ensure that the URL entered in the Internet Explorer address bar (3) matches the Site Address (4) found in the Critical Settings panel.  The Site Address should represent the DNS alias of the MigrationStudio server.

Fully Qualified Domain Name

If the Site Address (1) uses the short DNS name, enter the fully qualified domain name (FQDN) instead:

  • Switch to Initial Setup in Admin as per the instructions in the previous step
  • Enter the FQDN of the MigrationStudio server in Site Address (1). For an internal installation, Site Address should be in the format: http(s)://Hostname.Domain/MigrationStudio/
  • Click the Save Changes button (2) to commit the changes
  • Reload MigrationStudio using the new FQDN-based site address in the Internet Explorer address bar (3)

Service Account Permissions

Ensure the MigrationStudio Uploads folder has the correct permissions:

  • Switch to Admin (1)
  • Select Initial Setup (2) from the vertical menu on the left
  • Make a note of the Upload Folder path (3)

  • Using a Windows account with administrator privileges, open Windows Explorer and navigate to the Upload Folder path
  • Ensure that the account running the IIS web service has "Modify" rights to the folder
    • Most installations will use an Active Directory Service Account, provided to MigrationStudio prior to installation (create a new Service Desk Ticket if the account details aren't available)
    • Installations based on SQL-authentication, typically PoCs, will use IIS_IUSRS

Further Support

If you require further support, please visit MigrationStudio's Service Desk at to search the knowledge base or create a new support ticket.