diff --git a/wallet/src/main/java/net/taler/wallet/exchanges/ExchangeListScreen.kt b/wallet/src/main/java/net/taler/wallet/exchanges/ExchangeListScreen.kt
index 7f64d6db..ce8ae1b6 100644
--- a/wallet/src/main/java/net/taler/wallet/exchanges/ExchangeListScreen.kt
+++ b/wallet/src/main/java/net/taler/wallet/exchanges/ExchangeListScreen.kt
@@ -102,13 +102,16 @@ fun ExchangeListScreen(
     val addErrorText = stringResource(R.string.exchange_add_error)
 
     LaunchedEffect(addError) {
-        addError?.getIfNotConsumed()?.let {
+        addError?.getIfNotConsumed()?.let { error ->
             addInProgress = false
+            // say why: unreachable host, not an exchange, or not a valid address
+            val reason = error.userFacingMsg
+            val message = if (reason.isEmpty()) addErrorText else "$addErrorText: $reason"
             if (showAddDialog) {
                 // Keep the dialog open so the user can correct the address.
-                addErrorMessage = addErrorText
+                addErrorMessage = message
             } else {
-                snackbarHostState.showSnackbar(addErrorText, duration = SnackbarDuration.Long)
+                snackbarHostState.showSnackbar(message, duration = SnackbarDuration.Long)
             }
         }
     }
@@ -352,8 +355,8 @@ fun AddExchangeDialog(
         },
         confirmButton = {
             TextButton(
-                onClick = { onConfirm(url) },
-                enabled = !loading,
+                onClick = { onConfirm(url.trim()) },
+                enabled = !loading && url.isNotBlank(),
             ) {
                 if (loading) {
                     CircularProgressIndicator(