If you are using the Wordpress Auto Update and seeing the could not copy error message,
Downloading update from https://downloads.wordpress.org/plugin/adsense-now-lite.4.60.zip?
Unpacking the update?
Could not copy file. adsense-now-lite/lang/uk_UE_easy-common.mo
the problem is due to the fact that you are
running out of allocated disk space. We found out on one of our friend's blog that her allocated space was exhausted and thus she was seeing this message.
Other problem could be due to Directory Permissions, but this is very remote a chance unless you have logged into shell account and have messed it up.