This error is thrown by dojo because the dojo.back
If a non-deferred mode module has a prerequisite on a deferred module, the server-side combiner framework promotes the deferred module to be non-deferred. The promoted module is then loaded entirely during the initial page rendering process. The module is treated as if it is not deferred, and all of its contributions to each extension point are displayed in view mode. Also, they are not included when any remaining deferred modules are loaded later.
- CSS contributions to the head are deferred and then inserted into the <head> element on demand by using the <link> element.
Do not use portal render request-dependent attributes here, as there is no guarantee that those attributes are available in all cases. For example, when used in deferred mode, the render context is not available.
Parent topic: Modules