--- cherrytree-0.99.37/src/ct/ct_actions_others.cc      2021-05-19 00:40:05.000000000 +0200
+++ cherrytree-0.99.37.new/src/ct/ct_actions_others.cc  2022-01-12 09:00:22.285981087 +0100
@@ -289,7 +289,7 @@
     if (link_entry.type == CtConst::LINK_TYPE_WEBS) { // link to webpage
         Glib::ustring clean_weblink = str::replace(link_entry.webs, "amp;", "");
         if (_pCtMainWin->get_ct_config()->weblinkCustomOn) {
-            std::string cmd = fmt::sprintf(_pCtMainWin->get_ct_config()->weblinkCustomAct, clean_weblink);
+            std::string cmd = fmt::sprintf(_pCtMainWin->get_ct_config()->weblinkCustomAct, std::string(clean_weblink));
             int retr = std::system(cmd.c_str());
             if (retr == -1) {
                 // Internal std::system error