CatLight automatically checks for updates from time to time. When network connection is absent, or application cannot connect to online service, update check fails. Error message should be logged in this situation. There is a bug in logging code for this rare type of messages that starts a recursive logging cycle. After that, application consumes up to 1.2 Gb memory and then terminates.
This problem should be fixed in v2.0 that is scheduled to be available in several weeks.
Meanwhile, you can just restart the application after that happens.