In AX 2012 R2, if you will see any errors like this one #Error in SSRS reports randomly, that means you have to do one of the 2 following solutions:
In AX 2012, the service account that is setup in the “BC Proxy account” have always to be used for the SSRS execution account, and SSRS services account.
As a workaround or troubleshooting step, you can add the BCP account to AX with Sys Admin rights, and the report should print properly. This however, is not a long term solution and is a workaround that you can utilize short term until you get the following hotfix installed that should correct the issue:
Apply this hotfix
KB Article Number (s) : 2844965
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