Thank you for your response. My maintenance plan script identifies which indexes can be rebuilt online and takes all indexes with over 30% fragmentation and rebuilds them. This is a pretty standard script. On all of my dev boxes with the same db this script runs fine. In production it does not. This is also not the first nvarchar column, there already were several columns with this data type in the table.

Can you think of any reason why this fails? Almost all of the tables contain LOB columns and the script has run fine for some time now.

Thanks again for all of your help, it is much appreciated.