WordPress 4.1 and Plguins

Hi, Since upgrading to WordPress 4.1, I can’t update my plugins (or add any new ones) and some of them are no longer working. I keep getting the following message when trying to update any or all of the plugins:

Removing the old version of the plugin…
Plugin update failed.
An error occurred while updating BuddyPress: Could not remove the old plugin.

I’m not hugely technical so please bare with me as I may need some additional step by step help.

Thanks for your help!

Laura