# Debugging "RuntimeError: Trying to backward through the graph a second time, but the buffers have already been freed."

**URL:** <https://discuss.pytorch.org/t/debugging-runtimeerror-trying-to-backward-through-the-graph-a-second-time-but-the-buffers-have-already-been-freed/10900>\
**Category:** autograd\
**Created:** [December 7, 2017, 5:42pm UTC](https://discuss.pytorch.org/t/debugging-runtimeerror-trying-to-backward-through-the-graph-a-second-time-but-the-buffers-have-already-been-freed/10900 "2017-12-07T17:42:58Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![jdhao](https://discuss.pytorch.org/user_avatar/discuss.pytorch.org/jdhao/32/2558_2.png) [@jdhao](https://discuss.pytorch.org/u/jdhao)\
**Post date:** [December 8, 2017, 1:53am UTC](https://discuss.pytorch.org/t/debugging-runtimeerror-trying-to-backward-through-the-graph-a-second-time-but-the-buffers-have-already-been-freed/10900/2 "2017-12-08T01:53:30Z")

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Have you searched the forum and read [this post](https://discuss.pytorch.org/t/runtimeerror-trying-to-backward-through-the-graph-a-second-time-but-the-buffers-have-already-been-freed-specify-retain-graph-true-when-calling-backward-the-first-time/6795/2), for example?

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_[View the full topic](https://discuss.pytorch.org/t/debugging-runtimeerror-trying-to-backward-through-the-graph-a-second-time-but-the-buffers-have-already-been-freed/10900)._