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The Installation Package Could Not Be Opened Error Occurs


Product Progress® Telerik® UI for ASP.NET AJAX


When installing Telerik UI or ASP.NET AJAX, an error that the installation package cannot be opened and that I have to contact the application vendor to verify the Windows installer package is valid occurs.

Error Message

This installation package could not be opened. Contact the Application vendor to verify that this is a valid windows installer package


The possible reasons for this issue may be the following:

  • The installation file got corrupt during the download.

  • The installation file was downloaded to a compressed folder and/or the Temp folder on the machine is compressed.


To solve this issue:

  1. Log in to your Telerik account and download the Telerik UI for ASP.NET AJAX installer again. To verify that the new download is not corrupt, use an md5 hash sum calculator, for example, the fciv utility is such a tool.

  2. Download the installation file to a non-compressed drive.

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