"Page doesn't exist" error is presented when clicking the Configure link for the App on the Installed Packages page.
In the latest version, we've included a Lightning Setup Wizard, which requires that My Domain is enabled in the Org. Please make sure you have that configured. More information on how to set My Domain up can be found here: https://help.salesforce.com/articleView?id=sf.domain_name_setup.htm&type=5.
After My Domain has been configured, please make sure the following has been done:
1) The user needs to have access to the E2CP LEX tab in their profile, so make sure the following is set to 'Visible.'
2) Under Object Settings in the user's profile, make sure that the tab called 'Email to Case Premium Setup' is set to 'Default On' instead of 'Hidden.'
3) Add the tabs to the E2CP App menu for visibility:
- Open E2CP via the App Launcher.
- Click on the pencil icon on the right-hand side of the screen to personalize your navigation bar.
- Click on "Add More Items."
- Search for "Email to Case Premium" and select the tabs below.
- Make sure the tab called "Email to Case Premium Setup" is also showing in the list, and move them to the top.
The tab named 'Email to Case Premium Setup' is the Setup Wizard for Lightning.
The tab named 'Email to Case Premium Settings' brings you to the Outbound Configurations page of the Setup Wizard with the old, Classic style pages.
The tab named 'Email to Case Premium Setup Wizard' brings you to the start of the Setup Wizard experience with the old, Classic style pages.
After this, upon clicking the 'Configure' link in the Installed Packaged page, you should be redirected to the Lightning Experience Setup Wizard.
If you're still having issues, please open a case with Internet Creations Support, and we will gladly help you solve this via subscriber access.