Extra notice: Nodes that do not upgrade to v21 will be disconnected AND services using the wrong PoW threshold will stop working
Just want to stress this some extra since it's the biggest coming change with possible disruption of services and voting weight. The following is from the [release notes](https://docs.nano.org/releases/current-release-notes/) but not all people read the small text.
Nodes upgrading to V21.0 will remain peered with nodes V19.0 and V20.0 on the network until the epoch v2 block distribution begins. **After the first epoch v2 block is distributed, all nodes not running V21.0 will no longer be able to participate on the network.** This distribution will occur once 90% of voting weight and key services on the network have upgraded. Communications around the progress towards this goal will be sent following the release.
More details about this network upgrade can be found on the [Network Upgrades page under the Upcoming upgrades section](https://docs.nano.org/releases/network-upgrades#increased-work-difficulty)
**All network participants are encouraged to upgrade to V21.0 as soon as possible to avoid disruption.**
The purpose of the epoch upgrade is to help ensure Quality of Service on the network by increasing the difficulty required for **send and change** blocks to be considered valid by the network (**8x compared to current**). To help offset the difficulty increase and add incentive to receive blocks so ledger pruning can be done more broadly in the future, the difficulty for **receive (and open) blocks** will simultaneously be reduced (**⅛ compared to current**).
**All proof of work done with an incorrect threshold will be invalid. This means libraries, tools and wallets using the old PoW level will stop working.** One library I know is used in multiple services, for example in nanovault, is the webGL-pow. I kindly ask the developer to look at [this PR](https://github.com/numtel/nano-webgl-pow/pull/1/files) which prepares for this change.
If you know more libraries or tools with hard coded threshold, please reach out to them. Be...