Gravity Support Forums Topic: Fatal Error when installing campaign monitor add on

Gravity Support Forums Topic: Fatal Error when installing campaign monitor add on https://legacy.forums.gravityhelp.com/topic/fatal-error-when-installing-campaign-monitor-add-on Gravity Support Forums Topic: Fatal Error when installing campaign monitor add on en-US Sun, 19 Apr 2026 20:26:08 +0000 http://bbpress.org/?v=1.0.1 <![CDATA[Search]]> q https://legacy.forums.gravityhelp.com/search.php Jamisoloman on "Fatal Error when installing campaign monitor add on" https://legacy.forums.gravityhelp.com/topic/fatal-error-when-installing-campaign-monitor-add-on#post-71821 Tue, 21 Aug 2012 07:46:16 +0000 Jamisoloman 71821@https://legacy.forums.gravityhelp.com/ Thanks Chris, I actually found it is because I'm using the Campaign monitor API to auto send posts to subscribers. All fixed now. Cheers Jami Chris Hajer on "Fatal Error when installing campaign monitor add on" https://legacy.forums.gravityhelp.com/topic/fatal-error-when-installing-campaign-monitor-add-on#post-71610 Sun, 19 Aug 2012 14:29:19 +0000 Chris Hajer 71610@https://legacy.forums.gravityhelp.com/ Sounds like you have another Campaign Monitor plugin installed. However, in version 1.4.1 of our add-on, there was logic added which was supposed to handle this potential problem. <a href="http://www.gravityhelp.com/gravity-forms-campaign-monitor-add-on-v1-4-1-released/" rel="nofollow">http://www.gravityhelp.com/gravity-forms-campaign-monitor-add-on-v1-4-1-released/</a> Please be sure you have the latest Campaign Monitor add-on (1.4.1) from us, or, if you already do, please deactivate the other plugin and use ours exclusively. Jamisoloman on "Fatal Error when installing campaign monitor add on" https://legacy.forums.gravityhelp.com/topic/fatal-error-when-installing-campaign-monitor-add-on#post-71590 Sat, 18 Aug 2012 23:03:42 +0000 Jamisoloman 71590@https://legacy.forums.gravityhelp.com/ Hi Guys, I've just upgraded to a business account and subscribing to campaign monitor, however I'm receiving a fatal error when going to the Forms > Campaign Monitor menu Fatal error: Cannot redeclare CS_REST_SERIALISATION_get_available() (previously declared in /nfs/c06/h06/mnt/xxx/domains/domainname.com.au/html/wp-content/plugins/campaign_monitor/api/class/serialisation.php:5) in /nfs/c06/h06/mnt/xxx/domains/domainname.com.au/html/wp-content/plugins/gravityformscampaignmonitor/api/class/serialisation.php on line 13 Note: I changed our client number to 'xxx' and the clients domain to 'domainname' Can someone help?