> For the complete documentation index, see [llms.txt](https://knowledge.illumina.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://knowledge.illumina.com/instrumentation/nextseq-500-550/instrumentation-nextseq-500-550-troubleshooting-list/000002053.md).
# Troubleshooting a Flow Cell Registration Failed (Skew) warning on the NextSeq 500/550
The following warning message can occur during NextSeq 500/550 pre-run checks "Flow Cell Registration Failed (skew). No action necessary" (Figure 1).
This warning is caused by a software communication issue and generally does not impact performance.
**Figure 1.** Image of the NextSeq Control Software notifications tab with the warning "Flow Cell Registration Failed (skew). No action necessary".
**Troubleshooting steps:**
1. Monitor run until completion and review run specifications. Run specifications for NextSeq 500/550 are listed here [Specifications for the NextSeq 500/550.](/instrumentation/nextseq-500-550/instrumentation-nextseq-500-550-reference_material-list/000001942.md)
* If the run does not meet specifications, contact [Illumina Technical Support](https://www.illumina.com/company/contact-us.html#/united-states/technical-support).
2. Power cycle instrument before next run. For further information, see the Knowledge Base articles [How to Power Cycle the NextSeq 500/550.](/instrumentation/general/instrumentation-general-reference_material-list/000001972.md)
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| *For any feedback or questions regarding this article (Illumina Knowledge Article #2053), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000001972%20-%20Instrumentation%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |
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