I redeployed an old commit which was definitely working but due to improper version pinning on strapi dependency side it seems that it stoped working if redeploying the same code again. That’s kinda frustrating because this already happened several time to me with strapi.
After Upgrading strapi and all main plugins to 4.1.9 the error was gone.
I have same issue but after upgrading strapi to 4.1.9 have “Missing jwtSecret. Please, set configuration variable “jwtSecret” for the users-permissions plugin in config/plugins.js”
I have a similar issue.
I reinstalled the app and it worked, but after building some api tables, now all I see is a blank white page.
I’m getting the same issue, with strapi version 4.0.0. Any updates on this issue? Can anyone please share any workarounds? 
when I run yarn develop in my local everything is fine, but when I deployed it on the cloud, it stops working
on a fresh install, I have to run yarn build after creating the example-cms project or the blank white screen pops up.
Also, make sure your node is v14+.
Furthermore, this may be related to a plugin problem; do you have any plugins installed? I am leaning to strapi-stripe.
I have had 2 of 2 strapi projects give me this blank page after setting up everything.
Is there a way to backup our content-types?
I am having a similar issue after I get a blank screen I get a different error message
My error: TypeError: Cannot read properties of undefined (reading ‘allPermissions’)
I’ve solved it:
just created new project and copy api 
But I didn’t figure this out
You don’t lose any production data that way?
Anyone from Strapi team can help us?
In this way, the previous data will be lost, right?
It’s been a few days now has anyone found a solution or heard anything from the strapi team?
I have fixed the issue when I upgraded Strapi version to 4.1.11 and used node=14.19.1 & npm=6.14.16 without creating a new project. Hope this helps you all out too
Hey @webdev did you face the error " [Missing jwtSecret. Please, set configuration variable “jwtSecret” for the users-permissions plugin in config/plugins.js]" ?
@IloveCoding No, but I think you should add JWT_SECRET in your Config Vars and pull the value in config/plugins.js
"engines": {
"node": "14.19.1",
"npm": "6.14.16"
},
λ The engine "node" is incompatible with this module. Expected version "14.19.1". Got "16.13.2"
Right now you seem to have some success on this issue so I’d like to hear your thoughts on how I should proceed?
@wakywayne saying you have v14 installed, you should set that as the default node version. otherwise, install that and remove v16
Same as someone posted above. I fixed it by upgrading the version to 4.10.12. Btw, 4.0.6 and 4.1.8 don’t work for me.
And if you directly upgrade from 4.0.0 to 4.1.1+. Don’t miss the following setting, this is only mentioned in v4.1.8 migration guide.
You have to set jwtSecret in config/plugin.js
Strapi no longer populates default values for the admin JWT in
config/admin. Initial values are generated and stored in the .env file during project creation. Strapi no longer passes secrets to non-development environments, requiring users to set the secrets purposefully.
Still waiting for some offical solution from strapi team 
Please could you share a screenshot or briefly explain how you set JWTSecret. Thank you
if you are using Heroku to deploy your app, then set the environmental variable of jwt secret there.
I believe everything will work fine
As for the upgrades you only need to change the version number in your package.json file. you can find more details in the upgrade guide
but if you need to migrate then check out this documentation
Is this in regards when you are deploying your application, I believe that you need to set your Strapi URL ENV variable.
Check this article, here we use example where we deploy on Render. GitHub - derrickmehaffy/strapi-test-v4-render-deploy: Test deploying on render
Let me know if that helps. If you are having these issues when deploying, share you platform where you are deploying and your deployment setting to help us help you best.
I will also try to reproduce the error on the platform where you are trying to deploy.