This hotfix also applies to Microsoft SQL Server 2012 Reporting Services (SSRS 2012) and SQL Server 2014 Reporting Services (SSRS 2014).
You cannot input text that has more than 32,767 characters in any textboxes in the Report Query Designer in Microsoft SQL Server 2008 R2 Business Intelligence Development Studio (BIDS), SQL Server 2012 SQL Server Data Tools (SSDT), or SQL Server 2014 SQL Server Data Tools (SSDT). For example, assume that you try to create a new dataset. You use query designer, and you choose the Edit as Text option to input the query. In this situation, you cannot input a long query that has more than 32,767 characters.
This issue occurs because textboxes use the default setting of the TextBox.MaxLength property in Report Query Designer, which is 32,767 characters.
The issue was first fixed in the following cumulative update of SQL Server.
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server: