🎨 Fix #12724

src/main/java/org/b3log/solo/processor/console/PreferenceConsole.java

@@ -17,6 +17,7 @@
  */
 package org.b3log.solo.processor.console;
 
+import org.apache.commons.lang.StringUtils;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.Inject;
 import org.b3log.latke.logging.Level;
@@ -183,6 +184,12 @@ public class PreferenceConsole {
                 return;
             }
 
+            String hljsTheme = preference.optString(Option.ID_C_HLJS_THEME);
+            if (StringUtils.isBlank(hljsTheme)) {  // TODO: 在 v3.5.0 发布后可移除判空
+                hljsTheme = Option.DefaultPreference.DEFAULT_HLJS_THEME;
+                preference.put(Option.ID_C_HLJS_THEME, hljsTheme);
+            }
+
             String footerContent = "";
             final JSONObject opt = optionQueryService.getOptionById(Option.ID_C_FOOTER_CONTENT);
             if (null != opt) {