I can not find way to restrict users to have HTML in their posts while only Admins having it.
I think the real issue is to figure out why they were empty in the first place. When a user is created user:136 object and the entry in users:joindate should be both created.
In this case you will have to run a custom script to add the missing entries. Place the following code in a javascript file name custom_scripts.js in your nodebb folder and run it with node custom_script.js
/* globals require, console, process */ 'use strict'; const nconf = require('nconf'); nconf.file({ file: 'config.json', }); nconf.defaults({ base_dir: __dirname, views_dir: './build/public/templates', upload_path: 'public/uploads', }); const db = require('./src/database'); db.init(async (err) => { if (err) { console.log(`NodeBB could not connect to your database. Error: ${err.message}`); process.exit(); } await addMissingJoinDates(); console.log('done'); process.exit(); }); async function addMissingJoinDates() { const batch = require('./src/batch'); const user = require('./src/user'); const total = await db.sortedSetCard('users:joindate'); let counter = 0; await batch.processSortedSet('users:joindate', async (uids) => { const userData = await user.getUsersFields(uids, ['uid', 'joindate']); counter += uids.length; await db.sortedSetAddBulk( userData.map(data => ['users:joindate', data.joindate, userData.uid]) ); console.log(`${counter} / ${total}`); }, { batch: 500, }); }