ReCaptcha plugin needs a public key error

I get this this error message in Joomla's control panel:
" ReCaptcha plugin needs a public key to be set in its parameters. Please contact a site administrator."

This happened after having installed "System – GK Contact" plugin.

The control panel is not accessible anymore, so I can't remove that plugin.

Any suggestions please?

Fixed:

I changed the lines:
if($this->params->get('use_recaptcha') == 1) {
To :
if($this->params->get('use_recaptcha') == 0) {

In: /public_html/plugins/system/plg_gkcontact/plg_gkcontact.php

To be able to access Joomla's control panel. Then I disabled the plugin gkcontact, and changed the lines above back to "== 1".

Later I disable the recaptcha option in gkcontact (since, I don't want to have it), and finally as the last step, I enabled gkcontact.

Hi

Ok. Thank You for sharing this solution with us. I believe someone will benefit from this thread.

Thank You very much!
After hours of reading gibberish across forums
your quck and precise instructions had helped me.
Thanks again
Robert

Thank you - your advice was very useful and you are therefore a life saver!