When viewing forums and or after making a purchase I get error codes

Viewing forums error:

Error: Class 'IPS\Theme\hook38_tmp' not found (0)
#0 /var/www/html/106155/system/Theme/Theme.php(820): IPS\_Theme->compileTemplates('forums', 'front', 'topics')
#1 /var/www/html/106155/applications/forums/modules/front/forums/topic.php(553): IPS\_Theme->getTemplate('topics')
#2 /var/www/html/106155/system/Dispatcher/Controller.php(101): IPS\forums\modules\front\forums\_topic->manage()
#3 /var/www/html/106155/system/Content/Controller.php(50): IPS\Dispatcher\_Controller->execute()
#4 /var/www/html/106155/applications/forums/modules/front/forums/topic.php(39): IPS\Content\_Controller->execute()
#5 /var/www/html/106155/system/Dispatcher/Dispatcher.php(153): IPS\forums\modules\front\forums\_topic->execute()
#6 /var/www/html/106155/index.php(13): IPS\_Dispatcher->run()
#7 {main}

Making a purchase error:

INSERT INTO `nexus_licensekeys` ( `lkey_type`, `lkey_active`, `lkey_uses`, `lkey_activate_data`, `lkey_generated`, `lkey_identifier`, `lkey_purchase`, `lkey_member`, `lkey_max_uses`, `lkey_key` ) VALUES ( 'sulk', true, 0, '[]', 1646090485, 'name', 31, 1, 1, NULL )
IPS\Db\Exception: Column 'lkey_key' cannot be null (1048)
#0 /var/www/html/106155/system/Db/Db.php(938): IPS\_Db->preparedQuery('/*y319285::y319...', Array)
#1 /var/www/html/106155/system/Patterns/ActiveRecord.php(487): IPS\_Db->insert('nexus_licenseke...', Array)
#2 /var/www/html/106155/applications/nexus/sources/Purchase/LicenseKey.php(201): IPS\Patterns\_ActiveRecord->save()
#3 /var/www/html/106155/applications/nexus/sources/Package/Product.php(399): IPS\nexus\Purchase\_LicenseKey->save()
#4 /var/www/html/106155/applications/nexus/extensions/nexus/Item/Package.php(846): IPS\nexus\Package\_Product->onPurchaseGenerated(Object(IPS\nexus\Purchase), Object(IPS\nexus\Invoice))
#5 /var/www/html/106155/applications/nexus/sources/Purchase/Purchase.php(951): IPS\nexus\extensions\nexus\Item\_Package::onPurchaseGenerated(Object(IPS\nexus\Purchase), Object(IPS\nexus\Invoice))
#6 /var/www/html/106155/applications/nexus/sources/Invoice/Invoice.php(1989): IPS\nexus\_Purchase->__call('onPurchaseGener...', Array)
#7 /var/www/html/106155/applications/nexus/modules/front/checkout/checkout.php(1636): IPS\nexus\_Invoice->markPaid()
#8 /var/www/html/106155/system/Helpers/Wizard/Wizard.php(181): IPS\nexus\modules\front\checkout\_checkout->_pay(Array)
#9 /var/www/html/106155/applications/nexus/modules/front/checkout/checkout.php(170): IPS\Helpers\_Wizard->__toString()
#10 /var/www/html/106155/system/Dispatcher/Controller.php(101): IPS\nexus\modules\front\checkout\_checkout->manage()
#11 /var/www/html/106155/applications/nexus/modules/front/checkout/checkout.php(57): IPS\Dispatcher\_Controller->execute()
#12 /var/www/html/106155/system/Dispatcher/Dispatcher.php(153): IPS\nexus\modules\front\checkout\_checkout->execute()
#13 /var/www/html/106155/index.php(13): IPS\_Dispatcher->run()
#14 {main}

One of your plugins or applications look to be causing the issue. Disable them all and enable them one by one to find the culprit. 

Looking at your database, it appears to be being caused by the 3rd party plugin "(TB) Show IP to Admins Only"