[Theme: Simple Grid] blanks Multisite dashboard

Hi when I activate the Simple Grid theme on the base site – attempting to access the Network dashboard or any submenu returns a blank page. Activating (not removing) an alternate theme brings it back. It doesn’t matter that Simple Grid remains activated on a subdomain site.

This makes it difficult and messy to administer the network.

Any pointers as to what bits of Simple Grid could be interfering with the Network dashboard and any workarounds?