I don't have a ulticontroller. I enable pronterface and used a shorter USB cable (18 inches). I just tried again and got another failure on the first layer at the end of a pass just like all of the others. Strange because I can print other objects without any issues.
Here is the log from the proterface and all of these were there before the failure and nothing changed during or after the failure.
< echo:Unknown command: ""
< echo:Unknown command:""
< echo:Active Extruder:0
< echo:Unknown command; "26"
< Error:No Line Number with checksum, Last Line:1045
same as above -> 1053
< Error:No Checksum with line number, Last Line: 1451
same as above -> 1521
same as above -> 1533
same as above -> 1545
< Error:No Line Number with checksum, Last Line:1557
same as above -> 1643