Many people have reported this issue in latest client versions but until it's fixed what you can do is start OSBot from command line with the following syntax
java -jar pathtojar -login osbotusername:osbotpassword -proxy ip:port:user:pass -bot username:pass:pin
or for proxies based on ip authentication with no user/pass
java -jar pathtojar -login osbotusername:osbotpassword -proxy ip:port -bot username:pass:pin
and this also enables you to start osbot in a special mode for low resources/cpu usage by executing
java -jar pathtojar -login osbotusername:osbotpassword -proxy ip:port:user:pass -bot username:pass:pin -allow lowresource,lowcpu
where pathtojar is the full relative or absolute path to the osbot client jar including the jar file
PS: pin must be entered, if your account doesnt have a pin, feel free to type 1234 or a random number