> 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-1000-2000/instrumentation-nextseq-1000-2000-troubleshooting-list/000003547.md).
# Universal Copy Service failed to validate the Output Folder error on the NextSeq 1000/2000
Universal Copy Service (UCS) copies sequencing output files from the run folder to BaseSpace Sequence Hub (if applicable) and the output folder.
**Error Language**: Universal Copy Service failed to validate the Output Folder. Retry and, if error persists, contact Illumina Technical Support.
Figure 1: Example of error in NextSeq 1000/2000 control software.\
**Troubleshooting steps:**
1. The NextSeq 1000/2000 Control Software requires at least two levels of nested folders to recognize the location of the output folder on the mounted network drive/external portable drive.
2. Make sure that the information in the fstab file is correct. (ie, group-level permissions are set correctly, and no syntax errors are present).
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| *For any feedback or questions regarding this article (Illumina Knowledge Article #3547), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000003547%20-%20Instrumentation%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |
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