diff --git a/app/src/main/java/com/openipc/pixelpilot/VideoActivity.java b/app/src/main/java/com/openipc/pixelpilot/VideoActivity.java
index cacfc1ba..2bbe6615 100644
--- a/app/src/main/java/com/openipc/pixelpilot/VideoActivity.java
+++ b/app/src/main/java/com/openipc/pixelpilot/VideoActivity.java
@@ -16,6 +16,7 @@
 import android.hardware.usb.UsbManager;
 import android.net.Uri;
 import android.net.VpnService;
+import android.net.wifi.WifiInfo;
 import android.net.wifi.WifiManager;
 import android.os.BatteryManager;
 import android.os.Build;
@@ -114,7 +115,6 @@ public class VideoActivity extends AppCompatActivity implements IVideoParamsChan
     private static final long MODEL_LITE2_BYTES = 23096891L;
     private static final String PREF_OD_CUSTOM_MODEL_URI = "od_custom_model_uri";
     private static final String PREF_OD_CUSTOM_MODEL_NAME = "od_custom_model_name";
-    private static WifiManager wifiManager;
     final Handler handler = new Handler(Looper.getMainLooper());
     final Runnable runnable = new Runnable() {
         public void run() {
@@ -170,8 +170,26 @@ public static int getBandwidth(Context context) {
                 Context.MODE_PRIVATE).getInt("bandwidth", 20);
     }
 
-    public static String wirelessInfo() {
-        int address = wifiManager.getConnectionInfo().getIpAddress();
+    /**
+     * IPv4 address on the device's own wifi, used to tell the user where to push a stream
+     * when no adapter is attached. Returns null when there is nothing to report.
+     *
+     * <p>Takes a Context rather than reading a static WifiManager that only
+     * {@link #initializeUI()} assigns: any other caller - or this one before onCreate has got
+     * that far - hits a NullPointerException, and this is called from
+     * WfbLinkManager.refreshAdapters().
+     */
+    public static String wirelessInfo(Context context) {
+        WifiManager manager =
+                (WifiManager) context.getApplicationContext().getSystemService(Context.WIFI_SERVICE);
+        if (manager == null) {
+            return null;
+        }
+        WifiInfo info = manager.getConnectionInfo();
+        if (info == null) {
+            return null;
+        }
+        int address = info.getIpAddress();
         return (address == 0) ? null : Formatter.formatIpAddress(address);
     }
 
@@ -324,7 +342,6 @@ private void initializeUI() {
         getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
         getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
 
-        wifiManager = (WifiManager) getSystemService(WIFI_SERVICE);
     }
 
     // ----------------------------------------------------------------------------
diff --git a/app/src/main/java/com/openipc/pixelpilot/WfbLinkManager.java b/app/src/main/java/com/openipc/pixelpilot/WfbLinkManager.java
index 8580be69..7a3b7995 100644
--- a/app/src/main/java/com/openipc/pixelpilot/WfbLinkManager.java
+++ b/app/src/main/java/com/openipc/pixelpilot/WfbLinkManager.java
@@ -102,7 +102,13 @@ public Map<String, UsbDevice> getAttachedAdapters() {
         }
 
         Map<String, UsbDevice> res = new HashMap<>();
-        for (UsbDevice dev : manager.getDeviceList().values()) {
+        Map<String, UsbDevice> attached = manager.getDeviceList();
+        // "No compatible wifi adapter found." is a common report, and the one thing needed to
+        // act on it - the adapter's vendor and product id - was not obtainable. sysfs is not
+        // readable by the shell on some devices (Horizon OS for one) and dumpsys usb does not
+        // list host devices there either, so the app is the only thing that can report it.
+        Log.i(TAG, "usb devices attached: " + attached.size());
+        for (UsbDevice dev : attached.values()) {
             boolean allowed = false;
             for (UsbDeviceFilter filter : filters) {
                 if (filter.productId == dev.getProductId() && filter.vendorId == dev.getVendorId()) {
@@ -110,6 +116,13 @@ public Map<String, UsbDevice> getAttachedAdapters() {
                     break;
                 }
             }
+            Log.i(TAG, String.format("  %s  %04X:%04X  %s %s  -> %s",
+                    dev.getDeviceName(),
+                    dev.getVendorId(),
+                    dev.getProductId(),
+                    String.valueOf(dev.getManufacturerName()),
+                    String.valueOf(dev.getProductName()),
+                    allowed ? "supported" : "NOT in usb_device_filter.xml"));
             if (!allowed) {
                 continue;
             }
@@ -164,7 +177,7 @@ public synchronized void refreshAdapters() {
             binding.tvMessage.setText(text);
             binding.tvMessage.setVisibility(View.VISIBLE);
 
-            String wifi = VideoActivity.wirelessInfo();
+            String wifi = VideoActivity.wirelessInfo(context);
             if (wifi != null) {
                 String local = "udp://" + wifi + ":5600";
                 binding.wifiMessage.setText(local);