[Defender] WooCommerce, MultiStore, Defender :: not playing together nicely in multisite environme

The plugins that appear to be involved with this error are:
- WooCommerce 3.5
- WooMultistore
- WPMU Defender
and possibly:
- WPMU Hummingbird
- WooCommerce ShipStation (although, I'm now thinking that was their own issue for not offloading ShipStation upon WooCommerce upgrade/deactivation/reactivation)

The odd part is that everything appears to work, when the above plugins are deactivated/reactivated in various combinations.

I'm also going to copy/paste this entire ticket and share with WPMU. (copied from WooMultiStore support ticket submission)

I'm also going to include link to a screenshot of a WooCommerce table status error, that's showing missing tables.  This was submitted re: ShipStation plugin issue w/ WooCommerce 3.5 upgrade, but I thought I'd include it. It appears on all of the subsites, and I've never seen it before.
https://www.dropbox.com/s/dvo3751cr4bb2no/WooCommerce_MissingTables.jpg?dl=0
###

I upgraded to WooMultiStore v2 yesterday.  I was already on WooCommerce 3.5. 

here's a little background...

I was going to submit a support ticket last week, as I noticed that MultiStore was having a conflict with WPMU Defender.  It went away after I deactivated Defender, and I simply didn't have the time then to submit a support ticket then.  We haven't ever seen any issues due to Defender in the past, so this was very new.  (I'd also like to note, we use WPMU Cloner, for each starting store.  The only real reason why we Clone each store from a Vanilla setup, is so that we don't have to setup all of the WooCommerce settings for each new store we build.  This is the same practice that we've been using for a few years).

...everything appeared to be running correctly at that point.
###
skip ahead to a few days ago...

I initially had a fatal error upon upgrading to WooCommerce 3.5, due to the WooCommerce ShipStation plugin.  It appeared that was due to improper deactivation of the ShipStation plugin, because everything worked again after each store's tables were upgraded.  Everything was back up, all plugins were activated again, and no errors were being thrown.

I was editing a menu on the most recently cloned store.  When I deleted it, the following error was thrown.  I renamed the WooMultiStore folder (to deactivate), deactivated Defender, reactivated WooMultiStore... then, was able to enable Defender again, but this error was displayed on the page header (although, the plugin was activated network level).  There's the complete error info from the log down below.

Fatal error: Cannot declare class WP_Defender, because the name is already in use in /home/hilinemerch/public_html/multi/wp-content/plugins/wp-defender/wp-defender.php on line 16

### 

[30-Oct-2018 13:01:46 UTC] PHP Fatal error:  Uncaught Error: Call to a member function get_type() on boolean in /home/hilinemerch/public_html/multi/wp-content/plugins/woocommerce-multistore/include/class.admin.product.php:632

Stack trace:
#0 /home/hilinemerch/public_html/multi/wp-includes/class-wp-hook.php(286): WOO_MSTORE_admin_product->process_product_delete('171')
#1 /home/hilinemerch/public_html/multi/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array)
#2 /home/hilinemerch/public_html/multi/wp-includes/plugin.php(453): WP_Hook->do_action(Array)
#3 /home/hilinemerch/public_html/multi/wp-includes/post.php(2590): do_action('before_delete_p...', '171')
#4 /home/hilinemerch/public_html/multi/wp-includes/nav-menu.php(262): wp_delete_post('171')
#5 /home/hilinemerch/public_html/multi/wp-admin/nav-menus.php(251): wp_delete_nav_menu(Object(WP_Term))
#6 {main}  thrown in /home/hilinemerch/public_html/multi/wp-content/plugins/woocommerce-multistore/include/class.admin.product.php on line 632

[30-Oct-2018 13:07:31 UTC] PHP Warning:  fopen(/home/hilinemerch/public_html/multi/wp-content/plugins/woocommerce-multistore/woocommerce-multistore.php): failed to open stream: No such file or directory in /home/hilinemerch/public_html/multi/wp-includes/functions.php on line 4848

[30-Oct-2018 13:07:31 UTC] PHP Warning:  fread() expects parameter 1 to be resource, boolean given in /home/hilinemerch/public_html/multi/wp-includes/functions.php on line 4851

[30-Oct-2018 13:07:31 UTC] PHP Warning:  fclose() expects parameter 1 to be resource, boolean given in /home/hilinemerch/public_html/multi/wp-includes/functions.php on line 4854

[30-Oct-2018 13:14:43 UTC] PHP Warning:  Cannot assign an empty string to a string offset in /home/hilinemerch/public_html/multi/wp-includes/class.wp-scripts.php on line 426

[30-Oct-2018 13:15:03 UTC] PHP Warning:  Cannot assign an empty string to a string offset in /home/hilinemerch/public_html/multi/wp-includes/class.wp-scripts.php on line 426

[30-Oct-2018 13:15:25 UTC] PHP Warning:  Cannot assign an empty string to a string offset in /home/hilinemerch/public_html/multi/wp-includes/class.wp-scripts.php on line 426

[30-Oct-2018 13:15:44 UTC] PHP Warning:  Cannot assign an empty string to a string offset in /home/hilinemerch/public_html/multi/wp-includes/class.wp-scripts.php on line 426

[30-Oct-2018 13:15:53 UTC] PHP Warning:  Cannot assign an empty string to a string offset in /home/hilinemerch/public_html/multi/wp-includes/class.wp-scripts.php on line 426

[30-Oct-2018 13:21:00 UTC] PHP Warning:  Cannot assign an empty string to a string offset in /home/hilinemerch/public_html/multi/wp-includes/class.wp-scripts.php on line 426

[30-Oct-2018 13:22:58 UTC] PHP Fatal error:  Uncaught Error: Call to a member function get_type() on boolean in /home/hilinemerch/public_html/multi/wp-content/plugins/woocommerce-multistore/include/class.admin.product.php:632

Stack trace:
#0 /home/hilinemerch/public_html/multi/wp-includes/class-wp-hook.php(286): WOO_MSTORE_admin_product->process_product_delete(7933)
#1 /home/hilinemerch/public_html/multi/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array)
#2 /home/hilinemerch/public_html/multi/wp-includes/plugin.php(453): WP_Hook->do_action(Array)
#3 /home/hilinemerch/public_html/multi/wp-includes/post.php(2590): do_action('before_delete_p...', 7933)
#4 /home/hilinemerch/public_html/multi/wp-content/plugins/wp-hummingbird/core/modules/class-module-minify.php(1001): wp_delete_post(7933)
#5 /home/hilinemerch/public_html/multi/wp-content/plugins/wp-hummingbird/core/modules/class-module-minify.php(889): WP_Hummingbird_Module_Minify->clear_files()
#6 /home/hilinemerch/public_html/multi/wp-content/plugins/wp-hummingbird/admin/class-admin-n in /home/hilinemerch/public_html/multi/wp-content/plugins/woocommerce-multistore/include/class.admin.product.php on line 632

[30-Oct-2018 13:23:03 UTC] PHP Warning:  Cannot assign an empty string to a string offset in /home/hilinemerch/public_html/multi/wp-includes/class.wp-scripts.php on line 426

[30-Oct-2018 13:23:11 UTC] PHP Fatal error:  Cannot declare class WP_Defender, because the name is already in use in /home/hilinemerch/public_html/multi/wp-content/plugins/wp-defender/wp-defender.php on line 16

[30-Oct-2018 13:23:11 UTC] PHP Fatal error:  Cannot declare class WP_Defender, because the name is already in use in /home/hilinemerch/public_html/multi/wp-content/plugins/wp-defender/wp-defender.php on line 16

[30-Oct-2018 13:24:22 UTC] PHP Fatal error:  Uncaught Error: Call to a member function get_type() on boolean in /home/hilinemerch/public_html/multi/wp-content/plugins/woocommerce-multistore/include/class.admin.product.php:632

Stack trace:
#0 /home/hilinemerch/public_html/multi/wp-includes/class-wp-hook.php(286): WOO_MSTORE_admin_product->process_product_delete(7933)
#1 /home/hilinemerch/public_html/multi/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array)
#2 /home/hilinemerch/public_html/multi/wp-includes/plugin.php(453): WP_Hook->do_action(Array)
#3 /home/hilinemerch/public_html/multi/wp-includes/post.php(2590): do_action('before_delete_p...', 7933)
#4 /home/hilinemerch/public_html/multi/wp-content/plugins/wp-hummingbird/core/modules/class-module-minify.php(1001): wp_delete_post(7933)
#5 /home/hilinemerch/public_html/multi/wp-content/plugins/wp-hummingbird/core/modules/class-module-minify.php(889): WP_Hummingbird_Module_Minify->clear_files()
#6 /home/hilinemerch/public_html/multi/wp-content/plugins/wp-hummingbird/admin/class-admin-n in /home/hilinemerch/public_html/multi/wp-content/plugins/woocommerce-multistore/include/class.admin.product.php on line 632

[30-Oct-2018 13:24:29 UTC] PHP Fatal error:  Uncaught Error: Call to a member function get_type() on boolean in /home/hilinemerch/public_html/multi/wp-content/plugins/woocommerce-multistore/include/class.admin.product.php:632

Stack trace:
#0 /home/hilinemerch/public_html/multi/wp-includes/class-wp-hook.php(286): WOO_MSTORE_admin_product->process_product_delete(7933)
#1 /home/hilinemerch/public_html/multi/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array)
#2 /home/hilinemerch/public_html/multi/wp-includes/plugin.php(453): WP_Hook->do_action(Array)
#3 /home/hilinemerch/public_html/multi/wp-includes/post.php(2590): do_action('before_delete_p...', 7933)
#4 /home/hilinemerch/public_html/multi/wp-content/plugins/wp-hummingbird/core/modules/class-module-minify.php(1001): wp_delete_post(7933)
#5 /home/hilinemerch/public_html/multi/wp-content/plugins/wp-hummingbird/core/modules/class-module-minify.php(889): WP_Hummingbird_Module_Minify->clear_files()
#6 /home/hilinemerch/public_html/multi/wp-content/plugins/wp-hummingbird/admin/class-admin-n in /home/hilinemerch/public_html/multi/wp-content/plugins/woocommerce-multistore/include/class.admin.product.php on line 632

[30-Oct-2018 13:24:41 UTC] PHP Warning:  fopen(/home/hilinemerch/public_html/multi/wp-content/plugins/wp-defender/wp-defender.php): failed to open stream: No such file or directory in /home/hilinemerch/public_html/multi/wp-includes/functions.php on line 4848

[30-Oct-2018 13:24:41 UTC] PHP Warning:  fread() expects parameter 1 to be resource, boolean given in /home/hilinemerch/public_html/multi/wp-includes/functions.php on line 4851

[30-Oct-2018 13:24:41 UTC] PHP Warning:  fclose() expects parameter 1 to be resource, boolean given in /home/hilinemerch/public_html/multi/wp-includes/functions.php on line 4854

[30-Oct-2018 13:24:41 UTC] PHP Fatal error:  Uncaught Error: Call to a member function get_type() on boolean in /home/hilinemerch/public_html/multi/wp-content/plugins/woocommerce-multistore/include/class.admin.product.php:632

Stack trace:
#0 /home/hilinemerch/public_html/multi/wp-includes/class-wp-hook.php(286): WOO_MSTORE_admin_product->process_product_delete(7933)
#1 /home/hilinemerch/public_html/multi/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array)
#2 /home/hilinemerch/public_html/multi/wp-includes/plugin.php(453): WP_Hook->do_action(Array)
#3 /home/hilinemerch/public_html/multi/wp-includes/post.php(2590): do_action('before_delete_p...', 7933)
#4 /home/hilinemerch/public_html/multi/wp-content/plugins/wp-hummingbird/core/modules/class-module-minify.php(1001): wp_delete_post(7933)
#5 /home/hilinemerch/public_html/multi/wp-content/plugins/wp-hummingbird/core/modules/class-module-minify.php(889): WP_Hummingbird_Module_Minify->clear_files()
#6 /home/hilinemerch/public_html/multi/wp-content/plugins/wp-hummingbird/admin/class-admin-n in /home/hilinemerch/public_html/multi/wp-content/plugins/woocommerce-multistore/include/class.admin.product.php on line 632

###
The following is added to the error.log when Defender is re-activated on the Network level
###

[30-Oct-2018 13:24:46 UTC] PHP Warning:  fopen(/home/hilinemerch/public_html/multi/wp-content/plugins/wp-defender/wp-defender.php): failed to open stream: No such file or directory in /home/hilinemerch/public_html/multi/wp-includes/functions.php on line 4848

[30-Oct-2018 13:24:46 UTC] PHP Warning:  fread() expects parameter 1 to be resource, boolean given in /home/hilinemerch/public_html/multi/wp-includes/functions.php on line 4851

[30-Oct-2018 13:24:46 UTC] PHP Warning:  fclose() expects parameter 1 to be resource, boolean given in /home/hilinemerch/public_html/multi/wp-includes/functions.php on line 4854

[30-Oct-2018 13:24:46 UTC] PHP Fatal error:  Uncaught Error: Call to a member function get_type() on boolean in /home/hilinemerch/public_html/multi/wp-content/plugins/woocommerce-multistore/include/class.admin.product.php:632

Stack trace:
#0 /home/hilinemerch/public_html/multi/wp-includes/class-wp-hook.php(286): WOO_MSTORE_admin_product->process_product_delete(7933)
#1 /home/hilinemerch/public_html/multi/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array)
#2 /home/hilinemerch/public_html/multi/wp-includes/plugin.php(453): WP_Hook->do_action(Array)
#3 /home/hilinemerch/public_html/multi/wp-includes/post.php(2590): do_action('before_delete_p...', 7933)
#4 /home/hilinemerch/public_html/multi/wp-content/plugins/wp-hummingbird/core/modules/class-module-minify.php(1001): wp_delete_post(7933)
#5 /home/hilinemerch/public_html/multi/wp-content/plugins/wp-hummingbird/core/modules/class-module-minify.php(889): WP_Hummingbird_Module_Minify->clear_files()
#6 /home/hilinemerch/public_html/multi/wp-content/plugins/wp-hummingbird/admin/class-admin-n in /home/hilinemerch/public_html/multi/wp-content/plugins/woocommerce-multistore/include/class.admin.product.php on line 632