I hate to cross post, but I wasn\'t getting any progress with this on serverfault and there appears to be a lot more activity with regard to reporting services here.
I\'
The path under which you can find Report Server Service logs could be different, such as: C:\Program Files\Microsoft SQL Server\MSRS12.MSSQLSERVER\Reporting Services\LogFiles
In this logs you can find errors that happened after generating the report itself. For instance, if the Reporting Services user needs to write the report as a CSV file after a subscription and it lacks the necessary authorization, the only place where you can find the description of the error is in these logs, while the history of the Job connected with the subscription and the Execution Log will tell you that the Report was correctly generated (nothing about saving the report).