Wordpress custom UPS Label Printing code issues after upgrading from 4.7 to 4.9.5

I am a web designer/developer who has multiple clients. I have a good understanding of PHP/MYSQL, CSS, etc. Enough to have an intelligent conversation about a project and/or build a small application and do some debugging. However, I don't want to sit down and write the code myself. I make my money getting new clients, providing them with new or rebuilt websites, email, hosting, etc and I am very busy with that. Today I am requesting assistance on a Wordpress website that had custom code added about 2 years ago. The customization was affected when I upgraded Wordpress from 4.7 to 4.9.5. The customization allowed users to register to the website as a 'Contributor' and gain access to the website admin area (a customized version) so that they could print pre-paid UPS labels. After the upgrade, the customized are that they were able to access is no longer showing up after they sign in. Instead they get what you would normally expect to see when registering as a 'contributor' instead of the custom area that was created for UPS Label printing. The code to actually print the label and all that goes with it should still be working fine. The issue seems to be just getting to the right area. I am attaching pictures of the 4.7 version which is on a test domain (not the actual live website). This version is working properly. Go to: [login to view URL] and follow the instructions on the attached images so that you can see how this is supposed to work. The account you will use is 'warmantus' and the password is in one of the images. As you will see, you can log in and print UPS labels. address bar after login looks like: ../wp-admin/[login to view URL] On the live website which has been upgraded to 4.9.5 when you log in with 'warmantus' you get the wrong admin area which doesn't have any of the tabs for printing UPS labels. (see attached image [login to view URL]). address bar after login looks like: ../wp-admin/ I will provide access to the Live website once the project is ready to start.