Hi, thank you for using Intuit ProFile Community

The latest version of ProFile, (2020.1.1) has access to 2011 returns for creating or opening those returns, therefore a 2011 return should open on a windows 10 installation of ProFile. If you cannot create a new 2011 return try using Proreg, instructions are here.

If a prepared 2011 T1 will not open, look in the backup folder to see if there is a backup for the file: the original may be corrupt

Hope this helps