Problema Convert Board

[Pasquale-Pako]

Sera a tutti ho aggiornato il phpbb3 da 3.0.9 a 3.0.10 e tutto ok poi mi dice di convertire il board ma qua che devo mettere??

Board path:
This is the relative path on disk to your former board from the root of this phpBB3 installation.

ho messo /forum ma mi da questo errore:

Could not find path to your former board. Please check your settings and try again.
» .../forum was specified as the source path.
The table prefix needs to be the one used by the software you are converting from.
» Specified table prefix was phpbb_.

mi aiutate per favore grazie mille