A bug after upgrading Opencart to 2.3.0.2

Hello there,
After upgrading Opencart to the 2.3.0.2 version I'm having a bugs when a client do a purchase
Fatal error: Uncaught exception 'Exception' with message 'Error: Could not load model shipping!' in /home2/spicesco/public_html/system/storage/modification/system/engine/loader.php:180 Stack trace: #0 [internal function]: Loader->{closure}(Array, Array) #1 /home2/spicesco/public_html/system/engine/proxy.php(25): call_user_func_array(Object(Closure), Array) #2 /home2/spicesco/public_html/catalog/model/journal2/checkout.php(497): Proxy->__call('getQuote', Array) #3 /home2/spicesco/public_html/catalog/model/journal2/checkout.php(497): Proxy->getQuote(Array) #4 [internal function]: ModelJournal2Checkout->getShippingMethods() #5 /home2/spicesco/public_html/system/storage/modification/system/engine/loader.php(189): call_user_func_array(Array, Array) #6 [internal function]: Loader->{closure}(Array, Array) #7 /home2/spicesco/public_html/system/engine/proxy.php(25): call_user_func_array(Object(Closure), Array) #8 /home2/spicesco/public_html/catalog/controller/journal2/checkout.php(554): Proxy->__call('getShippingMeth...', Array) # in /home2/spicesco/public_html/system/storage/modification/system/engine/loader.php on line 180


In addition,the first page of the administration dashboard is not showing up