Troubleshooting an error related to InstrumentMaintenanceState.xml on the NextSeq 500/550

The following error may appear when an error is detected in the Instrument Maintenance State File. This results in the control software failing to initialize and power cycling does not resolve the issue.

If this occurs after manually altering the InstrumentMaintenanceState.xml file, the error language states

"While loading Instrument Maintenance State File "C:ProgramData\Illumina\NextSeq\InstrumentMaintenanceState.xml" Originally caused by: The string".

If this occurs after performing an upgrade to Windows 10/NextSeq Control Software (NCS) v4.0.0+ NCS v4.0.1 on an instrument that requires air filters, the error language states:

"While loading Instrument Maintenance State File C:\ProgramData\Illumina\NextSeq\InstrumentMaintenanceState.xml. Originally caused by: Root element missing".

Troubleshooting steps:

1. Open and review the InstrumentMaintenanceState.xml file located in C:\ProgramData*\Illumina\NextSeq

   1. If the file has been manually altered, review the string format listed in the error message

      1. Confirm date and time are listed in YYYY-MM-DD and 24 hour clock.

   2. If the file appears blank, contact Illumina Technical Support to request a new copy.

      1. Once the correct file has been copied to the appropriate location, restart the NextSeq Control Software.

2. If the issue persists, contact Illumina Technical Support.

Blank version:

Incorrect Time Format:

This example lists time as 2024-07-03T5:45:52, time must be 24 hour clock, update to 2024-07-03T05:45:52

Correct Example: