# An error on loss.backward() -\> RuntimeError: could not create a primitive

**URL:** <https://discuss.pytorch.org/t/an-error-on-loss-backward-runtimeerror-could-not-create-a-primitive/117840>\
**Category:** autograd\
**Created:** [April 12, 2021, 12:02am UTC](https://discuss.pytorch.org/t/an-error-on-loss-backward-runtimeerror-could-not-create-a-primitive/117840 "2021-04-12T00:02:15Z")\
**Posts on this page:** 1\
**Showing post:** 6

<div class="post-metadata">

**Author:** ![ptrblck](https://discuss.pytorch.org/user_avatar/discuss.pytorch.org/ptrblck/32/1823_2.png) [@ptrblck](https://discuss.pytorch.org/u/ptrblck)\
**Post date:** [December 27, 2021, 8:47pm UTC](https://discuss.pytorch.org/t/an-error-on-loss-backward-runtimeerror-could-not-create-a-primitive/117840/6 "2021-12-27T20:47:20Z")

</div>

I don’t know, as I wasn’t able to reproduce or isolate another error with the same error message.  
Based on [this post](https://discuss.pytorch.org/t/runtimeerror-could-not-create-a-primitive/117519/4) I could find some references to potentially missing CPU instructions, but don’t know if that was indeed the root cause.

---

_[View the full topic](https://discuss.pytorch.org/t/an-error-on-loss-backward-runtimeerror-could-not-create-a-primitive/117840)._