Viewing MPOS Events in Windows Event Viewer (AX 2012 R3 and D365FO)

MPOS logs its events to different Event Viewer locations depending on which version you're running.

AX 2012 R3

Application and Services Logs → Microsoft → Windows → AppHost → AppTracing

By default, some of these logs are hidden. To turn them on:

1. Navigate to Application and Services Logs → Microsoft → Windows → AppHost.
2. Right-click AppHost and select View → Show Analytic and Debug Logs.

AX 7 / Dynamics 365 for Operations

Application and Services Logs → Microsoft → Dynamics → Commerce-ModernPos

Under this node you'll find Admin, Debug, and Operational logs. Operational is where errors show up; Debug is disabled by default but can be turned on the same way as above if you need more detail.

This came out of a discussion on the Dynamics AX Community forum, which is worth a read for more context.