UI Builder Page Fails to Load / 403 Forbidden ErrorsIssue <!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: #000000; } span { font-size: 12pt; font-family: Lato; color: #000000; } h2 { font-size: 24pt; font-family: Lato; color: black; } h3 { font-size: 18pt; font-family: Lato; color: black; } h4 { font-size: 14pt; font-family: Lato; color: black; } a { font-size: 12pt; font-family: Lato; color: #00718F; } a:hover { font-size: 12pt; color: #024F69; } a:target { font-size: 12pt; color: #6e9db4; } a:visited { font-size: 12pt; color: #7057C7; } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: block; max-width: 500px !important; width: auto; height: auto; } } When opening a page in UI Builder, the editor fails to load completely.Browser network logs may show failed API calls with 403 Forbidden response codes. Release<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: #000000; } span { font-size: 12pt; font-family: Lato; color: #000000; } h2 { font-size: 24pt; font-family: Lato; color: black; } h3 { font-size: 18pt; font-family: Lato; color: black; } h4 { font-size: 14pt; font-family: Lato; color: black; } a { font-size: 12pt; font-family: Lato; color: #00718F; } a:hover { font-size: 12pt; color: #024F69; } a:target { font-size: 12pt; color: #6e9db4; } a:visited { font-size: 12pt; color: #7057C7; } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: block; max-width: 500px !important; width: auto; height: auto; } } Applicable to Vancouver and later. Cause<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: #000000; } span { font-size: 12pt; font-family: Lato; color: #000000; } h2 { font-size: 24pt; font-family: Lato; color: black; } h3 { font-size: 18pt; font-family: Lato; color: black; } h4 { font-size: 14pt; font-family: Lato; color: black; } a { font-size: 12pt; font-family: Lato; color: #00718F; } a:hover { font-size: 12pt; color: #024F69; } a:target { font-size: 12pt; color: #6e9db4; } a:visited { font-size: 12pt; color: #7057C7; } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: block; max-width: 500px !important; width: auto; height: auto; } } The issue occurs when the Explicit Roles plugin is activated. This plugin introduces a new role: snc_internal, and updates Access Control Lists (ACLs) to use it.If the snc_internal role is not assigned appropriately, it can block essential GraphQL or REST API calls required by UI Builder, resulting in a 403 error. Resolution<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: #000000; } span { font-size: 12pt; font-family: Lato; color: #000000; } h2 { font-size: 24pt; font-family: Lato; color: black; } h3 { font-size: 18pt; font-family: Lato; color: black; } h4 { font-size: 14pt; font-family: Lato; color: black; } a { font-size: 12pt; font-family: Lato; color: #00718F; } a:hover { font-size: 12pt; color: #024F69; } a:target { font-size: 12pt; color: #6e9db4; } a:visited { font-size: 12pt; color: #7057C7; } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: block; max-width: 500px !important; width: auto; height: auto; } } To resolve the issue: Add the snc_internal role to the admin role: Navigate to User Administration > Roles.Open the admin role record.In the Contains Roles related list, add the snc_internal role.Save the record. (Optional workaround) If your environment allows it: Clone from an instance without the Explicit Roles plugin to one that is affected. Note: The Explicit Roles plugin cannot be uninstalled once activated.