diff --git a/libs/ardour/ardour/plugin_manager.h b/libs/ardour/ardour/plugin_manager.h
index 3f6b250b68..393b07e38b 100644
--- a/libs/ardour/ardour/plugin_manager.h
+++ b/libs/ardour/ardour/plugin_manager.h
@@ -302,6 +302,8 @@ private:
 
 	void reset_scan_cancel_state (bool single = false);
 
+	void get_all_plugins (PluginInfoList&) const;
+
 	bool no_timeout () const { return _cancel_scan_timeout_one || _cancel_scan_timeout_all; }
 
 	void detect_name_ambiguities (ARDOUR::PluginInfoList*);
diff --git a/libs/ardour/plugin_manager.cc b/libs/ardour/plugin_manager.cc
index 416624a7ce..13e43708fd 100644
--- a/libs/ardour/plugin_manager.cc
+++ b/libs/ardour/plugin_manager.cc
@@ -610,18 +610,8 @@ PluginManager::refresh (bool cache_only)
 }
 
 void
-PluginManager::detect_ambiguities ()
+PluginManager::get_all_plugins (PluginInfoList& all_plugs) const
 {
-	detect_name_ambiguities (_windows_vst_plugin_info);
-	detect_name_ambiguities (_lxvst_plugin_info);
-	detect_name_ambiguities (_mac_vst_plugin_info);
-	detect_name_ambiguities (_au_plugin_info);
-	detect_name_ambiguities (_ladspa_plugin_info);
-	detect_name_ambiguities (_lv2_plugin_info);
-	detect_name_ambiguities (_lua_plugin_info);
-	detect_name_ambiguities (_vst3_plugin_info);
-
-	PluginInfoList all_plugs;
 	if (_windows_vst_plugin_info) {
 		all_plugs.insert(all_plugs.end(), _windows_vst_plugin_info->begin(), _windows_vst_plugin_info->end());
 	}
@@ -646,6 +636,22 @@ PluginManager::detect_ambiguities ()
 	if (_lua_plugin_info) {
 		all_plugs.insert(all_plugs.end(), _lua_plugin_info->begin(), _lua_plugin_info->end());
 	}
+}
+
+void
+PluginManager::detect_ambiguities ()
+{
+	detect_name_ambiguities (_windows_vst_plugin_info);
+	detect_name_ambiguities (_lxvst_plugin_info);
+	detect_name_ambiguities (_mac_vst_plugin_info);
+	detect_name_ambiguities (_au_plugin_info);
+	detect_name_ambiguities (_ladspa_plugin_info);
+	detect_name_ambiguities (_lv2_plugin_info);
+	detect_name_ambiguities (_lua_plugin_info);
+	detect_name_ambiguities (_vst3_plugin_info);
+
+	PluginInfoList all_plugs;
+	get_all_plugins (all_plugs);
 	detect_type_ambiguities (all_plugs);
 
 	save_scanlog ();
@@ -2898,12 +2904,25 @@ PluginManager::get_all_tags (TagFilter tag_filter) const
 {
 	std::vector<std::string> ret;
 
+	PluginInfoList all_plugs;
+	get_all_plugins (all_plugs);
+
+	std::map<PluginType, std::set<std::string>> nfos;
+	for (auto const& nfo : all_plugs) {
+		nfos[to_generic_vst (nfo->type)].insert (nfo->unique_id);
+	}
+
 	PluginTagList::const_iterator pt;
 	for (pt = ptags.begin(); pt != ptags.end(); ++pt) {
 		if ((*pt).tags.empty ()) {
 			continue;
 		}
 
+		if (nfos[(*pt).type].find ((*pt).unique_id) == nfos[(*pt).type].end ()) {
+			/* Plugin is not installed */
+			continue;
+		}
+
 		/* if favorites_only then we need to check the info ptr and maybe skip */
 		if (tag_filter == OnlyFavorites) {
 			PluginStatus stat ((*pt).type, (*pt).unique_id);