Ik zou een mailtje aan Boom Beach support sturen of een mailtje op hun forum plaatsen.
I get this error sometimes as well. Just trying (tapping 'Install) a second time worked for me in most cases.
Seems to be a Google Play issue. Having the same or similar error messages sometimes since one of the last updates.
Saw this recently for the first time as well with another app. Second attempt to install the app worked fine.
There is a useful list of play store errors on XDA and what you can do to fix them if retrying doesn’t work