do you see the same accounts in both wallets if you go to your dashboard?
Yes i see the accounts in the dashboard. I should also add that i have 2 wallets per client: default and wallet2.
I deleted the wallets on the client that I was getting that error on and restored backups for both wallets. After that I had to relaunch the client but I was able to send transactions from both wallets. However the problem then came back and now one of the wallets wont send transactions again.
So my guess is it has something to do with switching wallets in the client.