Unable to add Event Area

Hi,
Your plugin worked great on a local test environment (MAMP, OSX). Once placed on my host server (POWWEB), however, the metabox for adding event areas reports an unknown error and won’t save. I assume it is a problem with the host configuration, but I don’t know what. What do I need the host to do to make this work?
I have included the system report from the ‘live’ install below.
Thank-you for any help you can provide and please let me know if you need further information or access to the site to test. The ‘live’ site is also a test before the final is built.
Ian.

POWWEB OpenTicket System Report:
== Environment ==
* Home URL: [neutral] https://www.bigpictureplace.com
* Site URL: [neutral] https://www.bigpictureplace.com
* WC Version: [neutral] 2.2.11
* WP Version: [neutral] 4.1
* WP Multisite Enabled: [neutral] No
* Wev Server Info: [neutral] Apache/2 ++ HTTP/1.1
* PHP Version: [neutral] 5.5.6
* MySQL Version: [neutral] 5.5.32
* WP Acitve Plugins: [neutral] 7
* WP Memory Limit: [good] You have more than the required minimum memory of 64MB. Your current total is 256M.
* WP Debug Mode: [neutral] No
* WP Language: [neutral] en_US
* WP Max Upload Size: [neutral] No
* WP Max Post Size: [neutral] 20M
* PHP Max Execution Time: [neutral] 120
* PHP Max Input Vars: [neutral] 1000
* WP Uploads Writable: [good] Uploads directory IS writable
* Default Timezone: [neutral] UTC

== Software ==
* Active Plugins: [neutral]
+ Akismet (https://akismet.com/) by Automattic (https://akismet.com/),
+ Coming Soon Page & Maintenance Mode by SeedProd (https://www.seedprod.com) by SeedProd (https://www.seedprod.com),
+ [ON]: Gantry Template Framework (https://www.gantry-framework.org/) by RocketTheme (https://www.gantry-framework.org/),
+ Hello Dolly (https://www.ads-software.com/plugins/hello-dolly/) by Matt Mullenweg (https://www.ads-software.com/plugins/hello-dolly/),
+ [ON]: OpenTickets Community Edition (https://opentickets.com/) by Quadshot Software LLC (https://opentickets.com/),
+ [ON]: RokAjaxSearch (https://www.rockettheme.com) by RocketTheme, LLC (https://www.rockettheme.com),
+ [ON]: RokBox (https://www.rockettheme.com) by RocketTheme, LLC (https://www.rockettheme.com),
+ [ON]: RokCommon Library (https://www.rockettheme.com) by RocketTheme, LLC (https://www.rockettheme.com),
+ [ON]: RokSprocket (https://www.rockettheme.com) by RocketTheme, LLC (https://www.rockettheme.com),
+ [ON]: WooCommerce (https://www.woothemes.com/woocommerce/) by WooThemes (https://www.woothemes.com/woocommerce/)
* Acitve Theme: [neutral]
+ Myriad (https://www.rockettheme.com) by RocketTheme, LLC (https://www.rockettheme.com)

== Data ==
* Event Areas: [neutral]
+
* Ticket Products: [neutral]
+ #485 “VIP Access” (50.00) [0 EA],
+ #484 “General Admission” (30.00) [0 EA]

https://www.ads-software.com/plugins/opentickets-community-edition/