Hello George,
Thanks for writing in!
The PHP Warning messages clearly states that there is a warning from the plugin SG CachePress. You may need to temporarily deactivate the plugin to get rid of the warning messages.
Meanwhile, when you install the X theme, only Cornerstone plugin will get to installed automatically. You will need to validate X theme first before you can install the other bundled plugins. Once validated, you can select which bundled plugin to install in X > Validation > Extensions.
To validate X properly, please do the following:
1] Please login to your account and assign the license (https://theme.co/apex/licenses). You need to assign the license to your site using this url: https://www.example.com/. You have to make sure that url you just assign is the same as the one you have in your settings, Settings > General > Site Address
2] Go back to X > Validation, and insert the license code.
And please review the changes that we made on how you are going to validated your X theme because we made a big change in the process. Please check it out here: https://theme.co/apex/forum/t/setup-product-validation/55