Troubleshooting an Object Reference Error on MiSeq

Background

An "Object reference not set to an instance of an object" notification is a generic Windows framework error that may occur during any stage of sequencing or when the system is idle. The notification does not necessarily stop a sequencing run and it is often caused by communication issues between instrument subsystems or network connectivity problems.

Note: In some cases, this notification may co-occur with SIPDOWN errors. If the error occurs right at run start and references SIPDOWN, see article Troubleshooting SIPDOWN Errors on the MiSeq.

Troubleshooting steps:

1. If a run is in progress, let it continue and monitor run performance.

2. Power cycle the MiSeq upon run completion, following the steps in How to Power Cycle the MiSeq.

   1. Note: If a run is in progress, it cannot be resumed after the power cycle.

3. If the system re-initializes successfully, proceed with using the MiSeq system for sequencing.

4. If the instrument fails to initialize or any of the sequencing metrics look suboptimal, contact Illumina Technical Support.

   1. For guidance on evaluating the sequencing run performance, see the article Does my sequencing run look good?

For any feedback or questions regarding this article (Illumina Knowledge Article #1428), contact Illumina Technical Support [e-mail].