The ReddCoin network has evolved over the years, and our protocol has changed accordingly in two major ways.

When ReddCoin (RDD) transitioned to PoSV (Proof-of-Stake-Velocity) in 2015, the earlier clients were no longer able to securely add blocks or transactions to the new chain, due to the fundamental nature of the algorithm change.

Essentially, the "rules" of what is an a "acceptable block" or "acceptable transaction" changes with these significant network ugprades.

This happened again in 2019-2020 when the ReddCoin team launched and then activated PoSVv2 with a supermajority of 90% of observed blocks. At that time, all v2.x wallets ceased to be able to actively participate in the active chain on the ReddCoin network. 

What does this mean? 

if you have an older wallet, you may send transactions that "don't go", or "don't confirm". The above may be one cause.

You must upgrade your wallet before proceeding.

If you are running a version of v3.x OTHER than the current production version of 3.10.3, you will also need to upgrade. Each software release adds both features and fixes, and i nthis case, an issue estimating and assigning "too-low fees" sometimes results in transactions either not being sent correctly, or not being accepted and/or confirmed.

Again, you must upgrade before proceeding.

Any transactions in this state are NOT lost, and will be cleared from your wallet during the upgrade and recsync process.

See the below guides: