403 error - Forbidden when trying to create campaign


I am trying to create a campaign. I can reach step 3 and test the template, the emails to the test addresses actually go out.

I then click save and next, or save template changes, and I get:
403 Forbidden
A potentially unsafe operation has been detected in your request to this site.

anyone who knows what's happening?

I just found out that going all the way down and clicking on Confirmation arrow will take me to the next page. But then I am not sure my template was saved.
Can I view the campaign without going back into creation process? Preview the email that is going to be sent out?
mod_security on the server is off ... but I now found out by chance .. this is an app in my WP installation on same server. Called Wordfence (security) ... I never thought of that.
Thank you anyway, if not for your reply I wouldn't have looked at server logs and wouldn't have found
If any one is facing or seeing 403 Forbidden page after installation of your MW on CWP Control WebPanel go to Mod Security menu and select the domain name and on action tab move the on to off