It isn't your ISP Feline - SMF is a part of the operating system on the server that is used to get handles on the database, and whenever SMF cannot get an available handle it reports this error, it could be due to the connection limit like Shobet says, or it could be resource issues on the machine itself - impossible to tell from our side.
The "session timed out" error is different - that is reported by the web server. I've never had that one on this site myself, but it is usually because you've taken too long to post your message, although that is just a guess - it's hard to tell without seeing the logs or knowing how the application containers are set up on the web server.
