Reorganizing indexes problem

Helo, I'm running IDS11.5FC4 on Ubuntu and I'd like to reorganize some indexes. But when I launched ALTER FRAGMENT ON INDEX it fails with : SQL Error -949: Unable to alter fragmentation scheme when indexes disabled. Ok I'm fine with that but I check and enabled indexes on the concerned table but it doesn't changes anything. Could you help me please?

Hello something you can try (maybe is not the best way, but can work) drop the index and create it with the new structure or fragmentation strategy, in the new dbspaces that you want to use. It´s and idea.