Recently Microsoft has updated the Dynamics 365 Advanced Settings menu and got rid of options like Customizations, Solutions etc. It has become a challenge for Dynamics 365 developers to access the existing customizations or creating new solutions.
Following are options to access your customizations
1. New Interface at https://make.powerapps.com/
Steps to follow
a. Login using Dynamics 365 account on the above URL.
b. Click on Solutions menu
c. This will show you all your solutions including Default Solution.
d. If you still don’t find your solution, ensure that you have selected the correct Environment.
2. Classic Interface at https://make.powerapps.com/
Steps to follow
a. Login using Dynamics 365 account on the above URL.
b. Click on ‘Switch to classic’ option
c. This will allow you to access solutions in the classic layout
Be informed that after Oct 2020, Dynamics 365 Classic interface will not be available. All the Dynamics 365 customers need to migrate to Unified Interface apps.