Unable to trouble shoot

Hi
I am getting a white screen and am unable to edit or add new posts/pages. It is working with default theme.
When I use the troubleshooting plugin it is coming up with the following message and will not allow me to test for conflicting plugins. It is coming up with the same message for all plugins.

“When enabling the plugin, all-in-one-seo-pack, a site failure occurred. Because of this the change was automatically reverted.”

Can you please advise?

Thanks