Old Version of WPTouch broken access to Dashboard with 4.2.1

Hi,

Apologies if this has been explained elsewhere.
My dashboard no longer works.
This is what happened.
I’ve logged into the dashboard today and seen that an upgrade\update was available and the message strongly encouraged the upgrade but I did not upgrade any of the installed plugins before the WP upgrade.
I had installed to try the WPTouch. This plugin interface is what is causing my problem.
I’ve tried renaming the plugins folder in WP-content and this is even worse as I don’t get any interface at all after the renaming.
I think some folders were renamed “canonical” with this update\upgrade and these folders do not exist while I look thru the FTP admin interface.
I’m at a loss as to what has happened.
I never had an issue with upgrades before the install of this damned plugin.
Any help appreciated.

Cheers,

Marta