Major changes were done in script API: data string was added to all callbacks. C plugin API is already ok (there is data pointer for callbacks).
Therefore, all scripts for development version are incompatible with this new version. All official scripts have been updated on plugins page.

This data string must be added after each callback function in arguments of functions. For example in python :

weechat.hook_command("go", "Quick jump to buffers", "", "", "", "go_cmd")
(...)
def go_cmd(buffer, args):

becomes:

weechat.hook_command("go", "Quick jump to buffers", "", "", "", "go_cmd", "")
(...)
def go_cmd(data, buffer, args):