In Apple’s implementation of Apache/PHP, session.hash_function is set to sha512, which generates a 128-character hash. The DB table truncates at 32 (because SE4 is expecting md5 no sha512).

This triggers the following error in SocialEngine:

exception ‘Zend_Db_Statement_Mysqli_Exception’ with message ‘Mysqli statement execute error : Duplicate entry

To Fix this fault you can increase the value of number of character allowed in the ID column to 128 by following below steps:

• Go to table engine4_core_session of your site’s database.
• Run following command from “SQL” tab:

<span class="pl-s1"><span class="pl-c1">ALTER</span> <span class="pl-c1">TABLE</span> <span class="pl-s"><span class="pl-pds">`</span>engine4_core_session<span class="pl-pds">`</span></span> <span class="pl-c1">CHANGE</span> <span class="pl-s"><span class="pl-pds">`</span>id<span class="pl-pds">`</span></span> <span class="pl-s"><span class="pl-pds">`</span>id<span class="pl-pds">`</span></span> CHAR(<span class="pl-c1">128</span>);

</span>

This should now have fixed the error message you were seeing.

Looking for quality SocialEngine Hosting? Look no further than Arvixe Web Hosting