Environment
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Watch: Garmin Forerunner 965
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Mac: Mac mini → USB-C to VIA-based USB hub → original Garmin cable
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OS: macOS 15.6.1
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Apps: Garmin Express (works), BaseCamp (fails)
Problem
Garmin Express sees the watch and syncs fine, but BaseCamp shows “error communicating with your device.” macOS never shows the “BaseCamp would like to access files on a removable volume” dialog, so there’s no Files & Folders → Removable Volumes toggle for BaseCamp. Garmin’s docs say BaseCamp needs that permission on newer macOS.
What I tried
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Quit Express/Photos/OpenMTP, disabled Express auto-launch, started BaseCamp first, then plugged the watch in — still no permission prompt.
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Reset TCC permissions:
- tccutil reset SystemPolicyRemovableVolumes com.garmin.BaseCamp
- tccutil reset All com.garmin.BaseCamp
- Gave BaseCamp Full Disk Access manually
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Switched the watch between MTP and Garmin USB modes (manual says both supported).
What I see (logs & USB info)
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Mac sees the device as Garmin Composite Device (VID 0x091E), so the cable/port is data-capable (USB2 480 Mb/s).
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Unified logs show:
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Intermittent USB hub resets / hardware connection lost on the VIA hub.
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TCC activity for
SystemPolicyRemovableVolumeswhen BaseCamp tries to access the device, but no user prompt appears. -
Occasional single-client contention (MTP already opened) if Express is running.
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Sample log snippets
(IOUSBHostFamily) ... hardware connection lost (0x091e/0003/0001)
(com.apple.TCC:access) service=kTCCServiceSystemPolicyRemovableVolumes function="TCCAccessRequest"
(IOUSBHostFamily) ... already opened for exclusive access by pid ... BaseCamp
Has anyone hit this on macOS 15 (Sequoia)?
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How did you force the Removable Volumes prompt for BaseCamp?
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Any known BaseCamp compatibility issues on 15.6.1?
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Is a direct USB connection or powered hub required (VIA hub issue)?
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Any other fix I should try?