The expression must be of type 'string' - Alias issue in Essbase Studio

Encountered this issue while creating alias(new binding)

Reason : Due to different data type in Binding expression(expression must be of type 'String')

Converted binding expression to String using the below

'abs'(connection : \'TestingStudio'::'AgentInfo.dbo.EssbaseTestLoad'.'AgentId').toString

Now i have successfully created a new binding.