I am having the same problem.  I had created and funded an account on the web wallet a few weeks ago. Now that the upgrade has come out I can't gain access to the wallet I get the error "Transaction was not signed. Do you have a private key? [no_signers]". What hoops do I have to jump through to gain access again? I tried uploading the wallet backup but since I don't have the old downloaded wallet (was just using openledger) it looks like I don't have the "BTS 0.9.X KEY EXPORT FILE" which isn't the .bin.