I am able to replicate your issue.
I am attaching the following screen-cast for our developer to see to steps to produce this error.
Forum is blank when using with Evolve Plus theme.
There is actually a fatal error. The following is the error message.
Fatal error: Call to undefined function is_buddypress() in /Applications/MAMP/htdocs/evolve-plus-demo/wp-content/themes/evolve-plus/library/functions/basic-functions.php on line 3329
I will report this issue to our developers, Please wait for a fix in next theme version update.