diff --git a/src/main/java/net/rptools/maptool/client/MapTool.java b/src/main/java/net/rptools/maptool/client/MapTool.java
index 91e8b01391..68e3cd98f3 100644
--- a/src/main/java/net/rptools/maptool/client/MapTool.java
+++ b/src/main/java/net/rptools/maptool/client/MapTool.java
@@ -480,11 +480,15 @@ public static BackupManager getBackupManager() {
    * be called from any uncontrolled macros as there are both security and denial-of-service attacks
    * possible.
    *
+   * <p>This should not be called from any uncontrolled macros as there are both security and
+   * denial-of-service attacks possible.
+   *
+   * <p>This must be called on the AWT thread.
+   *
    * @param url the URL to pass to the browser.
    */
   public static void showDocument(String url) {
-    if (Desktop.isDesktopSupported()) {
-      String lowerCaseUrl = url.toLowerCase();
+    if (Desktop.isDesktopSupported() && Desktop.getDesktop().isSupported(Desktop.Action.BROWSE)) {
       String urlToBrowse = url;
       Desktop desktop = Desktop.getDesktop();
       URI uri = null;
@@ -492,8 +496,8 @@ public static void showDocument(String url) {
         uri = new URI(urlToBrowse);
         if (uri.getScheme() == null) {
           urlToBrowse = "https://" + urlToBrowse;
+          uri = new URI(urlToBrowse);
         }
-        uri = new URI(urlToBrowse);
         desktop.browse(uri);
       } catch (Exception e) {
         MapTool.showError(I18N.getText("msg.error.browser.cannotStart", uri), e);
diff --git a/src/main/java/net/rptools/maptool/client/ui/htmlframe/HTMLWebViewManager.java b/src/main/java/net/rptools/maptool/client/ui/htmlframe/HTMLWebViewManager.java
index 7f4becc55a..1e2fdbb421 100644
--- a/src/main/java/net/rptools/maptool/client/ui/htmlframe/HTMLWebViewManager.java
+++ b/src/main/java/net/rptools/maptool/client/ui/htmlframe/HTMLWebViewManager.java
@@ -585,8 +585,8 @@ private void fixHref(org.w3c.dom.events.Event event) {
           // Java bug JDK-8199014 workaround
           webEngine.executeScript(String.format(SCRIPT_ANCHOR, href.substring(1)));
         } else if (!href2.startsWith("javascript")) {
-          // non-macrolink, non-anchor link, non-javascript code
-          MapTool.showDocument(href); // show in usual browser
+          // non-macrolink, non-anchor link, non-javascript code. Show in usual browser
+          SwingUtilities.invokeLater(() -> MapTool.showDocument(href));
         }
         event.preventDefault(); // don't change webview
       }