diff --git a/public/css/style.css b/public/css/style.css
index 13246a3..4b60119 100644
--- a/public/css/style.css
+++ b/public/css/style.css
@@ -1487,8 +1487,17 @@ html, body {
 
 .plugins-panel__status {
   min-width: 3.5em;
+  max-width: 200px;
   color: #888;
   font-size: 11px;
+  /* Overrides the parent's nowrap: "Running…"/"Done" never wrap either
+     way, but a real RunError message (e.g. "plugin exited with status 1")
+     needs to, or it just overflows the flyout unreadably. */
+  white-space: normal;
+}
+
+.plugins-panel__status--error {
+  color: #c62828;
 }
 
 .plugins-panel__empty {
diff --git a/public/js/plugins.js b/public/js/plugins.js
index a43ab74..2c6a983 100644
--- a/public/js/plugins.js
+++ b/public/js/plugins.js
@@ -83,12 +83,23 @@ export class PluginsControl {
         east: bounds.getEast(),
       });
       const response = await fetch(`/api/plugins/${encodeURIComponent(plugin.name)}/run`, { method: "POST", body });
-      if (!response.ok) throw new Error(`run failed: ${response.status}`);
-      const { path } = await response.json();
-      notifyGpxStoreChanged(path);
+      // Every app.rb response on this route is JSON, success or error —
+      // the catch below is only for an infra-level failure in front of it
+      // (a proxy's own HTML error page, a dropped connection) that never
+      // reached app.rb at all.
+      const data = await response.json().catch(() => ({}));
+      if (!response.ok) throw new Error(data.error || `run failed: ${response.status}`);
+      notifyGpxStoreChanged(data.path);
       status.textContent = "Done";
+      status.classList.remove("plugins-panel__status--error");
     } catch (err) {
-      status.textContent = "Failed — see server log";
+      // Plugins::RunError's message (e.g. "plugin exited with status 1")
+      // reaches here as `data.error` above — nothing about a plugin run
+      // failure gets logged server-side (app.rb turns it into a plain 502
+      // JSON response, not an exception), so showing that message directly
+      // is the only way to see why, short of SSHing in to reproduce it.
+      status.textContent = err.message;
+      status.classList.add("plugins-panel__status--error");
     } finally {
       button.disabled = false;
     }