If the crashing occurs when attempting to enter caves, then that's something we're aware of. You can send a game log to support@tlopo.com so we can check if there's anything in the log that can help us determine the cause.
Make sure you open the log in a text editor such as Notepad and copy+paste the raw information in the log onto the email. We can't accept logs as attachments for security reasons.
Here is where to find logs:
PC: C:\Program Files (x86)\TLOPO\logs
Mac: ~/Library/Application\ Support/The\ Legend\ of\ Pirates\ Online/Game/logs