Hi! In Liberty, you want to run the server start (or run) command with --clean appended to it, like:
server start {serverName} --clean
In traditional Websphere:
Clear everything from the following locations, do not remove the directory itself, just the contents
WAS_HOME/profiles/profile_name/wstemp
WAS_HOME/profiles/profile_name/temp
WAS_HOME/profiles/profile_name/config/temp
#Support#SupportMigration#WebSphereLiberty