Could you please tell me the following:
1. Did the plugin crash right after installation? Or did you first use a coin adapter? Which coin adapter did you use? Did you connect it to a wallet?
2. You mentioned that you could not get the debug log. Have you enabled logging? https://codex.wordpress.org/Debugging_in_WordPress If there is an error 500 there should almost always be an error in your logs.
Without knowing what the error is it is hard for me to tell you anything more.
Looking forward to your reply.