The recent firmware update for Nintendo Switch, 5.0.0 (there's already a later version out), caused some major concerns as it "bricked" certain units. Others lost save data.
The reason for the problem is the use of well-known third-party manufacturers' docks like the ones from Nyko. Indeed, even if the accessory, cheaper than its official equivalent, which seemed to do a good job, has become incompatible with the latest firmware. The company said it was aware of the problem and is continuing to analyse the issue.
For its part, Nintendo stated that the firm could not evaluate its update on non-licensed products and accessories. If you've still got a warranty in place, you may send your bricked unit in for repair, but Nintendo strongly encourages the use of officially licensed products.
Thanks, Kotaku.