1) Did you try to change current role to one from the WordPress built-in set, like ‘author’?

2) What plugin do you use for the domain mapping?
At this plugin
description I found:

The login page will almost always redirect back to the blog’s original domain for login to ensure the user is logged in on the original network as well as the domain mapped one

So it seems that it’s not the real reason of a problem.

3) Could you add this line


to the begin to of ‘editor()’ function at user-role-editor-pro/includes/class-ure-lib.php, line #252?

So it will be seen as:

public function editor() {

        if (!$this->editor_init0()) {

When plugin works correct you should see this output after role change:
Array ( [action] => role-change [object] => role [user_role] => test_copy [ure_nonce] => c82168f082 )