i started the migration tool but it doesn't work

[temino]

 i have a 1.5 joomla website with vm old version and i need to create a new joomla 2.5 website with the last wm version
and i need to import all the products
i followed this guide and i imported on my db all the old db (the table prefix is different)
and i started the migration tool but it doesn't work i don't know why
can you help me?