There might be some configuration issue with a KNIME server. It takes multiple try to login. It prompts frequent error message that "Server ... cache update failed - loggin out." The second issue is that only one operation is allowed, such as deploying one KNIME workflow from client to server machine. It immediately logouts on its own. I take the two issues are related. Hopefully there is a way to resolve these issues.
Which version of KNIME Analytics Platform are you using? We recently increased the timeout for server operations which may help in your case. Have a look at your knime.ini for the line
If it's not present add it at the end of the file - or update to the latest version.