Bypassing pattern screen lock

Hey guys,
I have a device which i need to unlock (screen pattern lock).
I have no details regarding it's google account/PIN or any other method that allows unlocking it without using the pattern.
I tried downloading aroma file manager that allows access to the password file and delete it, but when i tried to install the aroma manager (through recovery, from an sd card) i keep getting these errors:
e: footer is wrong
e: signature verification failed

is there any way to solve this?
i can't access the device, so i can't enable debugging mode and things like that...is there any solution, besides wiping everything back to factory settings?

thanks!