Arena 5 isn't running for me on Mojave 10.14, I have some old projects that need Arena 5 because of plugins that aren't available for 6 and 7. I tried redownloading Arena 5 and installing it, but still doesn't work. Any suggestions?
Try renaming the Documents/Resolume Arena 5 folder to check if it's an issue with the settings.
If it doesn't help, please attach the mac crash log, and the Resolume log file from ~/Library/logs/Resolume/