Mrthdrb

in the backend, going to system->roles, adding a new role and setting it to custom permissions, the resource tree is empty.

Stepping through the code I can see, in module_user/Block/Role/Tab/Edit.php in function getTree() it returns three ACL-resources

public function getTree()
 
 $resources = $this->_aclResourceProvider->getAclResources();
 $rootArray = $this->_integrationData->mapResources(
 isset($resources[1]['children']) ? $resources[1]['children'] : []
 );
 return $rootArray;
 

The one used for the mapResources-call is Admin_Backend::all with an empty children array. Now in my opinion this leads to the resource tree being empty. Shouldn't there be an extra handling of the this role as it doesn't have explicitly assigned resources to it in the acl.xml? If I change the mapResources to use $resource[2] the tree is shown. But this feels a little awkward as I don't know what side effects that would have.

Any idea what's going wrong?

I had the same issue with the resources tree rendering blank, and I've found out that the issue was with the acl.xml file of one of the installed modules (it can also be from a theme).

In my case, the module's resources were not inside the Magento_Backend::admin resource tag:

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Acl/etc/acl.xsd">
<acl>
 <resources>
 <resource id="UOL_PagSeguro::Conciliation" title="Conciliation" sortOrder="10" />
 <resource id="UOL_PagSeguro::Abandoned" title="Abandoned" sortOrder="20" />
 <resource id="UOL_PagSeguro::Cancellation" title="Cancellation" sortOrder="30" />
 <resource id="UOL_PagSeguro::Refund" title="Refund" sortOrder="40" />
 <resource id="UOL_PagSeguro::Credentials" title="Credentials" sortOrder="50" />
 </resources>
</acl>
</config>

After making the changes such as placing the resources inside a group resource tag (one for all the module related resources), and also placing it inside the Magento_Backend::admin tag, fixed the problem.

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Acl/etc/acl.xsd">
<acl>
 <resources>
 <resource id="Magento_Backend::admin">
 <resource id="UOL_PagSeguro::admin" title="PagSeguro">
 <resource id="UOL_PagSeguro::Conciliation" title="Conciliation" sortOrder="10" />
 <resource id="UOL_PagSeguro::Abandoned" title="Abandoned" sortOrder="20" />
 <resource id="UOL_PagSeguro::Cancellation" title="Cancellation" sortOrder="30" />
 <resource id="UOL_PagSeguro::Refund" title="Refund" sortOrder="40" />
 <resource id="UOL_PagSeguro::Credentials" title="Credentials" sortOrder="50" />
 </resource>
 </resource>
 </resources>
</acl>
</config>

Finally, to find out the module/theme thats causing this issue, check their acl.xml files or try to disable one by one and check the roles & permissions page to see if the tree is visible again.

Remember to clear cache if you're not running in developer mode!

Open The path
/vendor/magento/module-user/Block/Role/Tab/Edit.php

And Change isset($resources[1]['children']) ? $resources[1]['children']
Intoisset($resources[2]['children']) ? $resources[2]['children']

Tree Will Showing

For More Details https://www.oolalaji.com

Had the same issue and the reason appeared to be some malware which came with google chrome extension. I would recommend to take a look inside the developer console of your browser.

You may also see the html source of the page and find the div element that will look like this:

<div class="tree x-tree" data-role="resource-tree" data-mage-init="..."

Under data-mage-init attribute there should be the json structure of the tree. If you do not see the huge json string inside data-mage-init attribute, search for the problem on the server side.