# FAQ: How can I tell if the model is fully loaded so that I can avoid "ReferenceError: member called after shutdown" in the Web Viewer?

**URL:** <https://forum.techsoft3d.com/t/faq-how-can-i-tell-if-the-model-is-fully-loaded-so-that-i-can-avoid-referenceerror-member-called-after-shutdown-in-the-web-viewer/1330>\
**Category:** HOOPS Visualize Web\
**Tags:** webviewer, knowledge-base, faq\
**Created:** [December 1, 2020, 5:00am UTC](https://forum.techsoft3d.com/t/faq-how-can-i-tell-if-the-model-is-fully-loaded-so-that-i-can-avoid-referenceerror-member-called-after-shutdown-in-the-web-viewer/1330 "2020-12-01T05:00:00Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![gabriel.peragine](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.techsoft3d.com/gabriel.peragine/32/1535_2.png) [@gabriel.peragine](https://forum.techsoft3d.com/u/gabriel.peragine)\
**Post date:** [December 1, 2020, 5:00am UTC](https://forum.techsoft3d.com/t/faq-how-can-i-tell-if-the-model-is-fully-loaded-so-that-i-can-avoid-referenceerror-member-called-after-shutdown-in-the-web-viewer/1330/1 "2020-12-01T05:00:00Z")

</div>

As part of the [Web Viewer class](https://docs.techsoft3d.com/communicator/latest/api_ref/viewing/classes/Communicator.WebViewer.html?#webviewer), there is a function called `waitForIdle()`:

[https://docs.techsoft3d.com/communicator/latest/api\_ref/viewing/classes/Communicator.WebViewer.html?#waitforidle](https://docs.techsoft3d.com/communicator/latest/api_ref/viewing/classes/Communicator.WebViewer.html?#waitforidle)

One possible solution is to call `shutdown()` in the returned Promise of `waitForIdle()` .