1 On Tools > Options > Portable Device Sync, "Windows Media compatible device d_WMDM.dll" > Configure > Options > File locations, change Music: to TEST.
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https://i.imgur.com/f2gxvc5.png
2 Click OK
3 Connect a WMDM (MTP) device.
4 Click Search, click Portable Device Sync (to refresh the device list) and verify "Windows Media compatible device d_WMDM.dll" has changed to "<device name> d_WMDM.dll".
5 Click Configure > Options > File locations, and inspect Music
Expected: "Music: TEST"
Observed: change is lost - Music: has reverted to installation default:
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https://i.imgur.com/B9bXMIu.png
Note: Not yet in Mantis.