Concatenate Strings SAP BO Design Studio 1.4

Hello experts,

we have just upgraded from 1.3 to 1.4. It seems everything is working fine but the script to concatenate strings.

For example, in 1.3, we were using:

               YearSAP = "K4" + Year

It was working fine and without problems.

Now in 1.4, the same code in the script editor doesn't show any error, but when execute it appears the standard error of scripting.

Any ideas?

Thanks in advance.