Please make sure that you have set your WordPress Permalinks to be /%postname%/ in Settings > Permalinks, as shown below:
You can also use a Custom Structure, such as: /%category%/%postname%/
... just make sure that the Custom Structure ends in /%postname%/
Current Plugin Version
Always check to be sure you are using the most current ClickFunnels plugin version. This can be verified on the Plugins Page of your WordPress Dashboard.
Further ClickFunnels WordPress Plugin Assistance
If you are experiencing an error that does not fall under under any of these categories, and you have already deactivated all of your plugins and re-enabled them one at a time, please submit a support ticket at https://support.clickfunnels.com/support/tickets/new