RippleX, the developer arm of Ripple, has urged node operators to upgrade to version 2.1.1. 

If they fail to update to the new version in a timely fashion, they will be amendment blocked.

The latest version of the reference server implementation of the XRPL became available a week ago. It has introduced an important amendment that is supposed to fix a critical Automated Market Maker (AMM) vulnerability. 

The AMM bug fix is going to be activated this Thursday, which is why RippleX is urging node operators to perform the upgrade. 

As reported by U.Today, the AMM amendment went live on the XRPL in May. David Schwartz, Ripple's chief technology officer, described this as a "significant moment" for the XRPL due to its potential to expand the decentralized finance (DeFi) ecosystem. The AMM mechanism allows ditching traditional order books in favor of individual liquidity pools. 

However, it wasn't smooth sailing for the new AMM feature. In late March, a critical bug was discovered that had hindered the feature's intended functionality. Transactions could not be executed properly due to an inconsistency in some AMM pools. XRPL users were advised against using the feature while the RippleX team was working on fixing the bug. Community participants of the likes of Sologenic were quick to close deposit functionality. 

The 2.1.1 release now includes the fixAMMOverflowOffer amendment that is meant to fix the major bug.