AdomdServer.Context.CheckCancelled throws exception after upgrading to SQL 2014


Recently we upgraded SQL 2008 R2 to SQL 2014, and also updated ASSP 1.3.7 to 2014 version.
But we ran into issues with ASSP.CreatePartitions stored proc where SSIS package (script task) fails with the error message "Internal error: The operation terminated unsuccessfully"

C# Script Snippet :
var cmd = @"call ASSP.CreatePartitions(""CubeName"", ""MeasureGroup"", ""[Date].[Date Hierarchy].[Month].Members"")";
var conn = new AdomdConnection(cs);
var foo = new AdomdCommand(cmd, conn);              
foo.ExecuteNonQuery(); // Exception here
I tried downloading ASSP source code and debugging, and eventually exception is thrown in Partition.cs whenever AdomdServer.Context.CheckCancelled(); is hit.

The exception is thrown very next second of function call, therefore it is less likely to be Timeout issue.

Note: The ASSP source code wasn't able to detect msmgdsrv.dll, and I manually added reference to the dll in location C:\Program Files\Microsoft SQL Server\MSAS12.<Instance>\OLAP\bin

Can someone please help me understand this issue, and how do I fix it ?

Thanks in advance.