> 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/microarray/general/microarray-general-troubleshooting-list/000009628.md).
# Troubleshooting the "Root element is missing" error on the iScan
If the error "Root element is missing" occurs on an iScan, this often indicates a corrupted RunSummary.xml file and the following message will present:
"**Root element is missing. (System.Xml.XmlException)**
Details:
* There is an error in XML document (0,0)"
**Figure 1.** Example of the "Root elements is missing" error.
A corrupted RunSummary.xml file might be blank. Check for file corruption in the following path:
* C:\RunSummary.xml
A non-corrupted RunSummary.xml file should look like this:
**Figure 2.** Non-corrupted RunSummary.xml file. Note that the value listed in the RunCount line will vary depending on the number of runs that the scanner has undergone.
**Troubleshooting steps:**
1. Make a copy of the RunSummary.xml file to the desktop and rename this as RunSummary - old.xml
* Contact [Illumina Technical Support](https://emea.illumina.com/company/contact-us.html#/united-states/technical-support) to obtain an uncorrupted new RunSummary.xml file or copy it from another functional iScan under the file path: C:\RunSummary.xml.
2. Replace the old RunSummary.xml file in the C:\ drive with a new or copied RunSummary.xml file.
3. Power cycle iScan and re-initialize the control software.
4. Re-scan the BeadChip(s).
5. If the issue is resolved, remove/delete the old RunSummary.xml file from the iScan computer.
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| *For any feedback or questions regarding this article (Illumina Knowledge Article #9628), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000009628%20-%20Microarray%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |
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