Problem with apt daemon. Apps disappeared, can't run any application, how do I fix it?

When в run synaptics package менеджер for example, I get

W: Not using locking for read only lock file /var/lib/apt/lists/lock  
W: Not using locking for read only lock file /var/lib/dpkg/lock  
E: Unable to write to /var/cache/apt/  
E: The package lists or status file could not be parsed or opened  

Can't поверьте new folder, can't upgrade my system. Ubuntu 15.04 running in в pen drive.