LG LGL55C User Manual page 236

Tools and Calendar
The microSD card can only be mounted for use by either the device or a
G
G
connected computer. Prior to accessing the card via a different method, it
must first be unmounted from its current device (phone or computer USB).
Important: The microSD card can only share a connection with one device at a
time, either your device or your computer (via its USB connection); not both. You
cannot browse the contents of the card via your device if they are currently being
browsed via your computer.
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