CloudSOC SysAdmin may receive an alert like this from CloudSOC and notice Box Securlet API events stopped being generated.
Box Administrator reduced permissions on the User Account used to activate Box Securlet
Box Administrator Should restore permissions on original Box User Account that was used to activate CloudSOC Box Securlet
If that doesn't resolve issue - deactivate and reactivate the Box Securlet using same original Box User Account that has permissions meeting requirements in Box Securlet Tech Doc.
Notes:
Box Admin User account highly recommended as described in Tech Doc
Box REST API Token refreshes 1 x every 24 hours - so effects of token refresh failure, email alert about reducing permissions, may not be seen until a day later