One user of free version of User Role Editor asked me via the Contact form:
– What is the process of switch from the version I am using now and the Pro Version, are there any migration issues I should be aware of?
I think that the answer I sent that user could be useful for other potential users of User Role Editor Pro. So I publish it here for your reference:
Read more Free and Pro versions compatibility ›

Version 4.5.1 of User Role Editor is the critical bug fix release. You did not install version 4.5 yet, as the next 4.5.1 update followed. The bug with multi-site super-admin access to the User Role Editor was fixed. Version 4.5. showed message “Insufficient permissions to work with User Role Editor” until add “manage_network_users” capability to the “Administrator” role. It is enough now to be the “Superadmin” at multi-site network.

The list of updates to version 4.5 published at 29.08.2013 includes the following:

• Direct checking of the “administrator” role is removed from the code to support ability to change User Role Editor access key capability.
  URE uses by default the “administrator” role for single site as the key capability to permit access to the User Role Editor.
  You may change this capability manually by replacing value of URE_KEY_CAPABILITY constant at includes/define_constants.php file. Pro version
  starting from 4.5 allows to change this key capability name (input your own, custom one) via User Role Editor settings page.
• The Hebrew translation is added. Thanks to atar4u.
• Pro version only: Ability to restrict access of different administrators to plugins activation/deactivation on the per plugin base is realized.
  Go to the user profile (user should have ‘activate_plugins’ capability) and select plugins to which you allow access for this user.
• Pro version: Gravity forms access restriction was re-factored and does not use JavaScript – it works on the SQL queries level now.
  In order apply form access restriction to the user it is enough that the user has any capability from the Gravity Forms capabilities list.

Read more User Role Editor version 4.5 is available ›

This is bug fix release. After applying to the user recently added Gravity Forms access restrictions user could not edit fields inside the form opened for editing. It is fixed now with version 4.4.1.

User Role Editor version 4.4 was released at August, 15th, 2013. This release includes:

• Bug fixed which prevented creation of current roles backup record during User Role Editor plugin installation and produced unexpected output (PHP notices).
• Pro version only: Users of “Gravity Forms” plugin may restrict users access to the Forms on per form basis.
• Pro version: User Role Editor license key is not shown now on the Setting page. User sees just word “Installed” after he saved it.

Read more User Role Editor version 4.4 ›