Troubleshooting an Object Reference Error on MiSeq

An "Object reference not set to an instance of an object" notification is a generic Windows framework error that can occur at any stage of sequencing or when the system is idle. It does not necessarily stop a sequencing run and it is often caused by communications issues between the instrument’s subsystems or problems with a network connection.

Troubleshooting steps:

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

2. If the error occurs right at run start and references SIPDOWN, please search for Knowledge Base article Troubleshooting SIPDOWN Errors on the MiSeq.

3. Power cycle the MiSeq upon run completion.

• MiSeq Power Cycle:

  1. Close MiSeq Control Software, shut down Windows, and turn off the instrument using the power switch on the back panel.

  2. Leave the instrument off for 5 minutes to allow all parts to completely power down.

  3. Turn on the instrument using the power switch on the back panel. The control software will initialize on its own once Windows fully loads.

• If the instrument fails to initialize or any of the sequencing metrics look suboptimal\*, contact Illumina Technical Support ([e-mail]).

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

\*For further information, search for Knowledge Base 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].