Make sure you are using Proto Stealth. While other stealths may support a few dashboards, they usually don't support the majority of them. If this fixes it stay with Proto.
Sign out of your profile. If this fixes it, try signing in to a non-live profile. If it still crashes the dashboard has bugs.
Also worth making sure the dashboard is correctly downloaded. Try redownloading it and make sure all the files are in their own folder and not renamed.
Try deleting the avatar update. This will not delete your actual avatar, and can be reinstalled through Xbox Live/a Local Update on the same version. To do this, hover over your internal memory (or HDD if you do not have internal memory) and press LB RB X LB RB X. Accept the prompt, your console will reboot afterwards. Your avatars will be gone, now try the dashboard. If it works the dashboard has bugs.
Some dashboards will only run on Devkits, you can try using the HvP2.xex plugin offline.
If on Xenia, dashboards later than 13604 (ie. anything Metro) can not* and probably will not run.
If none of these things help, the dashboard may be corrupted or you might have an edge case. Send me a message on Discord @adroz78 and I'll be happy to help.