You don’t need to run the WDMyCloud_WDCrack_1.0.bin file on a WD My Cloud Mirror to install the official multi bay unit third party apps. The My Cloud Mirror already supports third party apps. The WDMyCloud_WDCrack_1.0.bin is for the SINGLE BAY My Cloud v2.x versions which are a different model/version than the My Cloud Mirror.
See the following WD link for the third party apps the My Cloud Mirror supports out of the box:
http://setup.wd2go.com/?mod=faqs&device=mcm&faq=thirdParty
Edit to add: If your having trouble installing a My Cloud Mirror supported third party app you may want to post your My Cloud Mirror question to the dedicated My Cloud Mirror subforum since this subforum (My Cloud) is generally for the single bay My Cloud units.
https://community.wd.com/c/personal-cloud-storage/wd-my-cloud-mirror
