SQL Maintenance Rebuild Fails
Firstly, make sure the account executing the job has sufficient privileges to run alter index.  If that fails, then find the index "DTA_reports_indexcolumn_index2" and see if you can rebuild it yourself by hand.  If that works, then you may have another process hitting this table at the same time the index maintenance is running.  You'll have to look through what else is running around this time.

If rebuilding it by hand doesn't work, then explore what error you get, if you get one.  You might have to drop and recreate the index.  You might also run dbcc checkdb against the database to ensure that there's no corruption and run dbcc checktable against said table to ensure it's not corrupted.