Error MT1009: Could not copy the assembly

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last updated: 2017-03


This issue has been resolved in recent versions of Xamarin.iOS. However, if the issue occurs on the latest version of the software, please file a new bug with your full versioning information and full build log output.

As described in our Release Notes, this is a known issue in Xamarin.iOS 7.2.6. This issue is due to file permissions needing higher privileges when Xamarin.iOS is installed with a different user account then the developer's main account.

To workaround the issue, please open the on the Mac workstation and run the following command:

sudo chmod 0644 /Developer/MonoTouch/usr/lib/mono/2.1/monotouch.dll.mdb

Xamarin Workbook

If it's not already installed, install the Xamarin Workbooks app first. The workbook file should download automatically, but if it doesn't, just click to start the workbook download manually.