diff --git a/scenes/tagtinker_scene_barcode_input.c b/scenes/tagtinker_scene_barcode_input.c
index 46ef8bc..ea508e7 100644
--- a/scenes/tagtinker_scene_barcode_input.c
+++ b/scenes/tagtinker_scene_barcode_input.c
@@ -6,7 +6,8 @@
 
 static void unsupported_tag_back_cb(GuiButtonType type, InputType input_type, void* ctx) {
     UNUSED(type);
-    UNUSED(input_type);
+    /* Widget buttons report press, short and release alike; act once. */
+    if(input_type != InputTypeShort) return;
     TagTinkerApp* app = ctx;
     scene_manager_previous_scene(app->scene_manager);
 }
@@ -60,12 +61,30 @@ bool tagtinker_scene_barcode_input_on_event(void* ctx, SceneManagerEvent event)
 
 
 
-    app->selected_target = tagtinker_ensure_target(app, app->barcode);
+    int8_t idx = tagtinker_ensure_target(app, app->barcode);
 
-    if(app->selected_target >= 0) {
-        tagtinker_select_target(app, (uint8_t)app->selected_target);
+    if(idx < 0) {
+        /* The barcode already passed validation, so the only way left to fail
+         * is a full target list. Do not open the target actions with index -1. */
+        widget_reset(app->widget);
+        widget_add_string_element(
+            app->widget, 64, 10, AlignCenter, AlignTop, FontPrimary, "Target List Full");
+        widget_add_string_multiline_element(
+            app->widget,
+            64,
+            30,
+            AlignCenter,
+            AlignTop,
+            FontSecondary,
+            "Delete a saved tag\nto add a new one.");
+        widget_add_button_element(
+            app->widget, GuiButtonTypeLeft, "Back", unsupported_tag_back_cb, app);
+        view_dispatcher_switch_to_view(app->view_dispatcher, TagTinkerViewWidget);
+        return true;
     }
 
+    tagtinker_select_target(app, (uint8_t)idx);
+
     uint32_t target_scene = scene_manager_get_scene_state(
         app->scene_manager, TagTinkerSceneBarcodeInput);
     scene_manager_next_scene(app->scene_manager, target_scene);
diff --git a/scenes/tagtinker_scene_target_actions.c b/scenes/tagtinker_scene_target_actions.c
index 979802b..e39e022 100644
--- a/scenes/tagtinker_scene_target_actions.c
+++ b/scenes/tagtinker_scene_target_actions.c
@@ -29,6 +29,27 @@ static void show_target_details(TagTinkerApp* app, const TagTinkerTarget* target
     text_box_set_focus(app->text_box, TextBoxFocusStart);
 
     static char details_buf[256];
+
+    if(!target->profile.known) {
+        /* No table entry: size and colour are unknown, not 0x0 and Mono. */
+        snprintf(
+            details_buf,
+            sizeof(details_buf),
+            "--- Tag Info ---\n"
+            "Model: Unknown\n"
+            "Type: %u\n"
+            "Not in the profile table,\n"
+            "so Set Text, Set Image\n"
+            "and WiFi Plugins are\n"
+            "hidden for this tag.\n"
+            "Barcode:\n%s",
+            target->profile.type_code,
+            target->barcode);
+        text_box_set_text(app->text_box, details_buf);
+        scene_manager_next_scene(app->scene_manager, TagTinkerSceneTextBox);
+        return;
+    }
+
     uint16_t size_w = target->profile.width;
     uint16_t size_h = target->profile.height;
     tagtinker_profile_glass_size(&target->profile, &size_w, &size_h);
diff --git a/scenes/tagtinker_scene_transmit.c b/scenes/tagtinker_scene_transmit.c
index f5ab8fd..bf87eb3 100644
--- a/scenes/tagtinker_scene_transmit.c
+++ b/scenes/tagtinker_scene_transmit.c
@@ -457,6 +457,11 @@ static bool tx_send_color26_text(TagTinkerApp* app) {
 }
 
 static bool tx_stream_text_image(TagTinkerApp* app) {
+    /* A target without a table profile has no dimensions. Refuse here: both
+     * text paths below would otherwise call malloc(0), which the firmware
+     * treats as a fatal error. */
+    if(app->image_tx_job.width == 0U || app->image_tx_job.height == 0U) return false;
+
     if(tx_is_color26(app)) {
         return tx_send_color26_text(app);
     }
diff --git a/tagtinker_app.c b/tagtinker_app.c
index f6c5292..bb4fbb5 100644
--- a/tagtinker_app.c
+++ b/tagtinker_app.c
@@ -289,7 +289,10 @@ bool tagtinker_delete_target(TagTinkerApp* app, uint8_t index) {
 
 bool tagtinker_target_supports_graphics(const TagTinkerTarget* target) {
     if(!target) return false;
-    return target->profile.kind != TagTinkerTagKindSegment;
+    /* Only profile-table entries have real dimensions. A type code missing
+     * from the table leaves a zeroed profile (0x0, kind Unknown), so the app
+     * has no known display size to render text or images for. */
+    return target->profile.known && target->profile.kind == TagTinkerTagKindDotMatrix;
 }
 
 bool tagtinker_target_supports_accent(const TagTinkerTarget* target) {