Fatal error when trying to activate client dash

This problem has been addressed and will be released in a patch in the near future.

Sorry for any inconvenience.

Can you update to 1.6.7 and confirm this issue has been resolved?

Get the same error as OP.
Just downloaded version 1.6.7

I am getting a similar error having just downloaded and installed 1.6.7

Are there any known plugin conflicts?

Make sure your PHP is >= 5.3
Thats what is causing the problem. I have PHP 5.2.

i have the issue

A patch has been applied.

Please update to version 1.6.8 and see if the problem still persists.

Thanks!