implemented so that presentation modal will show

src/server/routes/page.js

@@ -220,13 +220,16 @@ module.exports = function(crowi, app) {
   }
 
   function addRenderVarsForPage(renderVars, page) {
+    const mongodb = require('mongodb');
     renderVars.page = page;
-    renderVars.page.creator = renderVars.page.creator.toObject();
     renderVars.revision = page.revision;
-    renderVars.revision.author = renderVars.revision.author.toObject();
     renderVars.pageIdOnHackmd = page.pageIdOnHackmd;
     renderVars.revisionHackmdSynced = page.revisionHackmdSynced;
     renderVars.hasDraftOnHackmd = page.hasDraftOnHackmd;
+    if (!mongodb.ObjectID.isValid(renderVars.page.creator)) {
+      renderVars.page.creator = renderVars.page.creator.toObject();
+      renderVars.revision.author = renderVars.revision.author.toObject();
+    }
   }
 
   async function addRenderVarsForUserPage(renderVars, page, requestUser) {