Add a "Troubleshooting" section to squeezeplay.md

Based on this forum post[1], add a new "Troubleshooting" section to the
documentation for SqueezePlay, which includes a workaround for getting
stuck at the "Libraries" screen during initial setup, when SqueezePlay
is run on a host that has more than one (active?) network interface.

[1]: https://forums.lyrion.org/forum/user-forums/general-discussion/1732269-squeezeplay-setup-8-4-1r1474-exe-windows-not-finding-server

Signed-off-by: Kevin Ernst <[email protected]>

Author: ernstki

docs/players-and-controllers/squeezeplay.md

@@ -64,4 +64,28 @@ Play Favorite 0-9	0-9
 
 ## Troubleshooting
 
-In case you encounter issues, please head over to the [forums](https://forums.lyrion.org/forum/user-forums/general-discussion/93838-squeezeplay-for-windows-with-asio-directsound-wasapi-and-wdmks-device-support) for assistance.
+_Some_ issues with SqueezePlay can be resolved by renaming (or removing) the `userpath` directory. Keep in mind that your installed apps and any menu customizations are stored in `userpath`, so it's best to make a backup before tinkering with it!
+
+For the various supported platforms, `userpath` is located in:
+
+* `%USERPROFILE%\AppData\Roaming\SqueezePlay` for Windows
+* `~/Library/Preferences/SqueezePlay` for macOS
+* and `~/.squeezeplay` for other Unix/Linux
+
+Removing/renaming this directory allows you to start with a fresh configuration, and go through the first-launch setup steps again.
+
+### No libraries showing up during initial setup
+
+SqueezePlay has a known issue[^fn1] on several platforms where it fails to receive the broadcast packets from instances of Lyrion Media Server on your local network, when the host running SqueezePlay has multiple network interfaces. This can leave you stuck at the "Libraries" screen during initial setup, with no obvious way to proceed.
+
+If it isn't possible to disable the other network interfaces during initial setup, try this workaround[^fn2]:
+
+1. press <kbd>D</kbd> (upper case) to get to the top-level menu
+2. choose _Settings_ → _Advanced_ (off the bottom of the default screen, so use arrow keys to scroll)
+3. choose _Networking_ → _Remote Libraries_
+4. enter the IP address of the desired LMS instance
+
+In case you encounter other issues, please head over to the [forums](https://forums.lyrion.org/forum/user-forums/general-discussion/93838-squeezeplay-for-windows-with-asio-directsound-wasapi-and-wdmks-device-support) for assistance.
+
+[^fn1]: https://forums.lyrion.org/forum/user-forums/general-discussion/1732269-squeezeplay-setup-8-4-1r1474-exe-windows-not-finding-server?p=1732388#post1732388
+[^fn2]: https://forums.lyrion.org/forum/user-forums/general-discussion/1732269-squeezeplay-setup-8-4-1r1474-exe-windows-not-finding-server?p=1745250#post1745250