# ImportError: cannot import name 'adjoint\_diff' from 'pennylane\_lightning.lightning\_qubit\_ops' **URL:** \ **Category:** PennyLane Help\ **Created:** [September 3, 2023, 6:49pm UTC](https://discuss.pennylane.ai/t/importerror-cannot-import-name-adjoint-diff-from-pennylane-lightning-lightning-qubit-ops/3386 "2023-09-03T18:49:55Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![David\_Liu](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/david_liu/32/1246_2.png) [@David\_Liu](https://discuss.pennylane.ai/u/David_Liu)\ **Post date:** [September 3, 2023, 6:49pm UTC](https://discuss.pennylane.ai/t/importerror-cannot-import-name-adjoint-diff-from-pennylane-lightning-lightning-qubit-ops/3386/1 "2023-09-03T18:49:55Z")
67 # check if cpp library for gradient computation exists 68 try: —\> 69 from pennylane\_lightning.lightning\_qubit\_ops import ( 70 adjoint\_diff, 71 StateVectorC64, ImportError: cannot import name ‘adjoint\_diff’ from ‘pennylane\_lightning.lightning\_qubit\_ops’ (/usr/local/lib/python3.10/dist-packages/pennylane\_lightning/lightning\_qubit\_ops.cpython-310-x86\_64-linux-gnu.so) Thank you. ---
**Author:** ![kevinkawchak](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/kevinkawchak/32/1801_2.png) [@kevinkawchak](https://discuss.pennylane.ai/u/kevinkawchak)\ **Post date:** [September 4, 2023, 3:51am UTC](https://discuss.pennylane.ai/t/importerror-cannot-import-name-adjoint-diff-from-pennylane-lightning-lightning-qubit-ops/3386/2 "2023-09-04T03:51:17Z")
Hello @David_Liu, Adjoint differentiation is typically applied with qnode decorators such as @qml.qnode(dev, diff\_method=“adjoint”). Could you provide more detail of where you would like to apply adjoint in the code? Reference: > **[Adjoint Differentiation | PennyLane Demos](https://pennylane.ai/qml/demos/tutorial_adjoint_diff/)** > > Learn how to use the adjoint method to compute gradients of quantum circuits. ---
**Author:** ![mlxd](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/mlxd/32/526_2.png) [@mlxd](https://discuss.pennylane.ai/u/mlxd)\ **Post date:** [September 4, 2023, 3:53pm UTC](https://discuss.pennylane.ai/t/importerror-cannot-import-name-adjoint-diff-from-pennylane-lightning-lightning-qubit-ops/3386/3 "2023-09-04T15:53:13Z")
Hi @David_Liu Can you provide the output of `qml.about()`? Also, if you have a minimum working script that reproduces the error this can help us identify the cause of the issue. I suspect this may be a version mismatch, and if so you can ensure your version of PennyLane and lightning.gpu are at the same version with `python -m pip install pennylane pennylane-lightning-gpu --upgrade`. ---
**Author:** ![David\_Liu](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/david_liu/32/1246_2.png) [@David\_Liu](https://discuss.pennylane.ai/u/David_Liu)\ **Post date:** [September 5, 2023, 1:28pm UTC](https://discuss.pennylane.ai/t/importerror-cannot-import-name-adjoint-diff-from-pennylane-lightning-lightning-qubit-ops/3386/4 "2023-09-05T13:28:57Z")
Thanks. It was a version mismatch between PennyLane and lightning.gpu from a library package. ---
**Author:** ![David\_Liu](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/david_liu/32/1246_2.png) [@David\_Liu](https://discuss.pennylane.ai/u/David_Liu)\ **Post date:** [September 5, 2023, 1:30pm UTC](https://discuss.pennylane.ai/t/importerror-cannot-import-name-adjoint-diff-from-pennylane-lightning-lightning-qubit-ops/3386/5 "2023-09-05T13:30:06Z")
Problem solved. It was a version mismatch between PennyLane and lightning.gpu from a library package. ---
**Author:** ![CatalinaAlbornoz](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/catalinaalbornoz/32/1196_2.png) [@CatalinaAlbornoz](https://discuss.pennylane.ai/u/CatalinaAlbornoz)\ **Post date:** [September 5, 2023, 9:00pm UTC](https://discuss.pennylane.ai/t/importerror-cannot-import-name-adjoint-diff-from-pennylane-lightning-lightning-qubit-ops/3386/6 "2023-09-05T21:00:49Z")
Thank you for letting us know that this solved your issue @David_Liu ! We have a new [PennyLane survey](http://bit.ly/PennyLane-Survey). We would love to know your thoughts about PennyLane in order to keep bringing you amazing features ✨.