Thanks for all the suggestions.
I have started Mango in SAFE mode (verified by looking in the ma.log file but I still can't get logged in.
I changed the env.properties file to set set db.web.start=true and tried to run the H2 web Console using web-console.sh -webAllowOthers but I get the message "Web Console server running at http://127.0.1.1:8081 (only local connections).
I thought the flag -webAllowOthers would let me connect to the Console from my laptop.
Is there something I'm missing in order to run the H2 database manager?