With Kee 184.108.40.206, KeePass 2.36, and KeePassRPC 220.127.116.11, unlimited new windows are generated at a rate of about 1 per second. None of the windows contain anything, and they continue generating until Firefox is closed. Upgrading the installed version of the KeePassRPC plugin to 18.104.22.168 solved the problem
Obviously, this is low priority, since this is incompatibility with an old version of KeePassRPC. However, I would suggest that similar compatibility issues are likely to arise in the future. Also, this is very undesirable behavior since it is difficult for the user to stop continued window generation. Therefore, Kee should be modified to keep this problem from recurring.