Check Constraint Issue

Hello, I am using ASPRunnerPro Enterprise Edition 7.1 build 12231.
I have converted a MS Access DB to a SQL Server 2008 R2. All fields seem to have converted properly. In using ASPR to build my app, I get to the Add section of the screen and attempt to add a record. ASPR gives me the following error:
The INSERT statement conflicted with the CHECK constraint "SSMA_CC$Receipts$CI Explanation$disallow_zero_length". The conflict occurred in database "DEU", table "dbo.Receipts", column 'CI Explanation'
I have checked the Field in SQL Server and it is set to nvchar(50) with Allow Nulls checked. In ASPR Editor inthe Add screen, I have the field set up to be View As (blank) and Edit As Text. All areas of the field parameters there is nothing changed from the default.
I cannot get past this error, do you have any suggestions please?

Thanks

Joe