In case you've been experiencing issues trading or adding liquidity on the Seadex, it may be due to an overloading issue on Moonriver's public RPC. Thankfully, there is a simple solution that will solve your problems.
Go to network settings in metamask and change your RPC Url to:
This should enable you to trade or add liquidity as you wish. Contact support if the problem persists and we will get right on it.