a) Take a screenshot of every single of your crew with official method(press printscreen and you will find the screenshot in C:\User\Your User Name\NavyField_NA\Screenshots
b) If the message "traffic to server is busy" pop up, click next and wait a few minutes without moving anywhere, normally it will loads successfully.
c) If you are depositing sailors into the HQ, and the message "traffic to server is busy" pop up, DON"T move anywhere, DON'T leave the shipyard, otherwise you risk losing your crew.
d) Don't put ships with crew on it into HQ. This is related to the sailor disappear issue. Try not to put ships into HQ, if you really have to, then take crew off from it first.
These are temporary solutions till we fix it. It involves complicated database issue so we need much time.