To quote the news page:
"Issues were encountered while testing flounder. This update may be broken (ie. not booting) on it, or the NAND may simply be failing on our test device as it was already slow and having issues before this update."
I can confirm my Nexus 9 (non-LTE) was affected by this, too. The update process went fine, but after that, it was stuck on the DivestOS logo.
Admittedly, it was slow before the update as well, but I attributed that to the CPU struggling with file system encryption rather than the NAND failing.
There must be something in the May 14th update that's preventing flounder from booting.
Edit: I've just reflashed the recovery and sideloaded the system from the previous update, device boots fine, confirming it's an issue with the May update.
To quote the news page: "Issues were encountered while testing flounder. This update may be broken (ie. not booting) on it, or the NAND may simply be failing on our test device as it was already slow and having issues before this update."
I can confirm my Nexus 9 (non-LTE) was affected by this, too. The update process went fine, but after that, it was stuck on the DivestOS logo. Admittedly, it was slow before the update as well, but I attributed that to the CPU struggling with file system encryption rather than the NAND failing.
There must be something in the May 14th update that's preventing flounder from booting.
Edit: I've just reflashed the recovery and sideloaded the system from the previous update, device boots fine, confirming it's an issue with the May update.