Environment:

JIRA 6.2.7
Service desk 2.0.2
MS SQL Server 2008 R2/2012 with the database collation type = SQL_Latin1_General_CP1_CI_AS or SQL_Latin1_General_CP437_CI_AI

When trying to add an existent user as an agent, JIRA throws the following error:

Error
There was a SQL exception thrown by the Active Objects library: 
Database: 
- name:Microsoft SQL Server 
- version:10.50.2500 
- minor version:50 
- major version:10 
Driver: 
- name:jTDS Type 4 JDBC Driver for MS SQL Server and Sybase 
- version:1.2.4 

java.sql.SQLException: Incorrect syntax near '-'.
Please contact the system administrator.

Although if the page is refreshed the user was successfully added as an agent.

Tested this on PostgreSQL and that does not occurs.

Workaround:

• Refer the correct database collation type in our Connecting JIRA to SQL Server 2008 documentation.
• Change to other external database.