I replicated the problem two users had in issue #99; installed the module and couldn't see the menu item at all.
I found that removing the parent="Magento_Backend::content" from the first add node in the menu.xml file got it working for me on my 2.2.1. build.
I don't think specifying a parent is necessary at that level because it will default to Magento Backend. For example, no parent is specified in the first add node in the following example:
I replicated the problem two users had in issue #99; installed the module and couldn't see the menu item at all.
I found that removing the parent="Magento_Backend::content" from the first add node in the menu.xml file got it working for me on my 2.2.1. build.
I don't think specifying a parent is necessary at that level because it will default to Magento Backend. For example, no parent is specified in the first add node in the following example:
https://www.magestore.com/magento-2-tutorial/how-to-create-admin-menu-in-magento-2/