Topic: mysql error after upgrade

[tariq]

I have upgraded from 5.5 to 5.6 but now I get an error as below:-

Jan 20 07:55:08 compudr mysql: ERROR 1061 at line 74: Duplicate key name 'category_category_name_idx'
Jan 20 07:55:08 compudr mysql.init: Loading 30mysql.create.horde.sql into mysql failed

I can access mysql client and see my databases etc. but my php pages have stopped working when they try to access the database. I have not changed any setting since upgrade. Can anyone please help, as my website is down due to to this problem!