# Troubleshooting a Flow Cell Door error on the NextSeq 500/550

The following error can appear during initialization or when setting up a sequencing run or wash. This can be a communication error, especially if the instrument had not been power cycled in a while.

**Error message**: "Exception generated from IxCmdIllumina.Spark.EmbeddedCommandSet.ix\_dlowcell\_door\_open : An error has occurred while executing command Originally caused by: An error has occurred while executing the command"

![](https://761066130-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FGM9W2DuBTgEXv1ClCm8H%2Fuploads%2Fgit-blob-5cf0fd56a038b0f1da884cb6359e6a263655ee70%2Fimage1.jpg?alt=media\&token=74c4890c-3523-471b-993d-d62e6ef5f740)

**Troubleshooting steps:**

1. Power cycle the NextSeq 500/550.
2. If instrument initializes without errors, the door can be tested as follows:
   1. Navigate to **Manage Instrument** and select **Unload Consumables**.
   2. Proceed with the wash setup.

* If the error does not re-appear, the instrument is cleared for continued use.
* If the error is recurring, contact [Illumina Technical Support](https://www.illumina.com/company/contact-us.html#/).

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| *For any feedback or questions regarding this article (Illumina Knowledge Article #3265), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000003265%20-%20Instrumentation%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |