NimbleOS 1.4.x went End of Support in May 2015. The email notification you will have received on this subject also states:
Nimble Storage will no longer be able to process AutoSupports, InfoSight and Case Automation for End of Software Support releases. All support automation for EOSS versions of Nimble OS will stop as of March 10, 2016.
Your Nimble array(s) have been identified as using an EOSS release and will be impacted if they are not updated to a current release of Nimble OS (e.g., 188.8.131.52) prior to March 10th. Please update your array(s) as soon as possible to avoid affecting the following Support Services:
- InfoSight use, including system monitoring and reporting, current and historical performance trending
- Automated and timely RMA processing
- Automated case creation
- Remote troubleshooting ability via Secure Tunnel
- Timely root cause identification and problem resolution
- Software supportability
I don't see any reason to stay on an old OS. When you have 2 minutes (literally), log in and download the upgrade, then once it's there take another 2 and initiate it. Updating the OS on Nimble has been super easy.
I did have one issue one time where the web interface wouldn't come back up, but support got that sorted out quickly. It didn't affect the environment at all, just the web admin interface.
PS: I'm not undermining your health issues, but writing this post probably took more time than doing an OS upgrade .
edit: I should add, maybe just check with support or the docs before proceeding since this version is pretty old. You may need to do an incremental update before applying the latest.