I'd rate it lower if I could, broke my site.

“Reset” function returns WordPress user roles to WordPress defaults, as it was just after WordPress installation.
When you press “Reset” button the detailed alert message is shown. It includes the text: ‘all changes made by you or your plugins will be lost’. So you should double think about the need to reinstall of all plugins if you decide to use the “Reset” function, or at least create a database backup.

I do not understand the negative reviews of such kind. Did you get some undocumented result of your action? You used the tool not valid way, skipped alert message and got the result, other than you expected.
It looks for me similar as someone slightly cut himself by the excellent knife from a great steel and then shout: “It is very bad knife, I’m disappointed!”.

I suggest you to read this post. It could help to resolve your problem:
https://www.role-editor.com/how-to-restore-deleted-wordpress-user-roles/

P.S. Pro version offers extended functionality, but it does not allow to change plugins permissions if you lost them.

@vladimir Garagulya, but why at the first place you make the reset button to reset all roles? You should only reset the changes that was done by the user, not all roles.

@mai: Let me to repeat: “Reset” function returns WordPress user roles to WordPress defaults, as it was just after WordPress installation.”. That is it returns roles to the zero state. Is it not the same as “only reset the changes that was done by the user” + “other plugins”?

But if you have plugins that have added roles, this will be broken by resetting all roles right?

What do the custom user roles default to on a reset? Do they all become contributors or editors or what?

If all the plugin custom roles disappear, what do they default to?

How do you get these custom roles back? Do you have to deactivate the plugin and reactivate it again and then go through all the users and reassign them to the custom role again?

Thanks

>> But if you have plugins that have added roles, this will be broken by resetting all roles right?
Yes, right. You may read about it at the warning message, which is show when you click “Reset” button.

>> What do the custom user roles default to on a reset?
User will have the same custom role assigned after reset. But that role will not exist. Administrator may reassign custom roles at the “Users” list using bulk operations.

>> If all the plugin custom roles disappear, what do they default to?
Reset operation does not re-assign roles to the users. Use bulk operation at “Users” page to do that.

>> How do you get these custom roles back?
You can not roll-back reset operation. Make database backup before try it. Some plugins like WooCommerce, re-creates its roles after re-activation, but some plugins don’t and stay in the broken state. You use reset operation on your own risk.

What happens when you deactivate this plugin? Does it leave all the roles/settings applied or does it reset them or?

Changes you made with User Role Editor are made directly to the WordPress database. When you deactivate URE all changes are leaved applied.