Blank Admin Page

I recently added a lifestyle hook to send an email after an entry is added. I went to deploy my new changes to heroku and now my admin panel is just a blank white page. Everything worked great in development mode and there are no errors in the heroku logs.

I’ve read through some of the other posts about fixes people had but none have worked. I’ve changed my versions of node/npm but still have the problem. The only other solution I’ve seen is to clone the repo and deploy a new version of Strapi while losing all data. This doesn’t seem like a great solution.

Does anyone have any other solutions or has Strapi said anything about this issue?

Error in console:

Uncaught ReferenceError: regeneratorRuntime is not defined
    at main.f7698254.js:2:1004432
    at Object.423 (main.f7698254.js:2:1005324)
    at e (main.f7698254.js:2:1011511)
    at Object.1261 (main.f7698254.js:2:984807)
    at e (main.f7698254.js:2:1011511)
    at Object.9321 (main.f7698254.js:2:994496)
    at e (main.f7698254.js:2:1011511)
    at main.f7698254.js:2:1011537
    at Object.94344 (main.f7698254.js:2:1011554)
    at s (runtime~main.66f28d16.js:1:141)

Hook code:

module.exports = {
  async afterCreate(event) {
    const { result, params } = event;
    // send new listing email to admins
    const emailTemplate = {
      subject: "New listing added and needs reviewed",
      text: `A new listing has been added and needs reviewed.
                        Title: <%= result.title %>
                        Contact: <%= result.contact_firstname %> <%= result.contact_lastname %>
                        Admin Panel`,
      html: `<p>A new listing has been added and needs reviewed.</p>
                    <p>Title: <%= result.title %></p>
                    <p>Contact: <%= result.contact_firstname %> <%= result.contact_lastname %></p>
                    <p><a href="[URL]/admin/content-manager/collectionType/api::listing.listing/<%= %>" target="_blank">Admin Panel</a></p>`,
    await strapi.plugins["email"]
        to: "[EMAIL]",
        result: _.pick(result, [

Man, Heroku is a thorn in my side right now. I updated Strapi locally with success, pushed to Heroku, and now my production app is dead. I’m thinking it would be easier and cheaper to go through a traditional hosting company that provides node.js app support. I wish I had an answer for you but I can share my grief.

So I was able to get it working again. I was on Strapi version 4.1.7 and followed the migration docs to upgrade to 4.1.8. They changed how the JWT_SECRET is handled. I also have the npm in the package.json set to 7.19.0. You then just need to make sure you have all your environmental variables in heroku.

Yep - Updating the ADMIN JWT SECRET per migration docs worked for me! Thanks!