runtime.app_key_missing
APP_KEY is not set
A mevcore app hosting error at the “start / health check” stage.
What it means
Laravel cannot run without an encryption key.
The build passed, but the app did not start or did not answer the health check.
Typical causes
- The app does not listen on 0.0.0.0 and the port from the PORT variable
- An environment variable is missing, or the database or Redis is not connected
- The start command is wrong or the process exits right away
How to fix it on mevcore
Add APP_KEY (base64:…) in the Environment tab.
- 1 Open the app in the mevcore panel: the Problems card on the overview shows this error and the log line it was found in.
- It is fixed on the “Environment” tab of the app.
- 2 After the fix, deploy again. If it fails again, the log ends with [mevcore] lines naming the new error code.
- 3 The "Ask AI" button next to the error prepares a request for ChatGPT or Claude: the error code, the end of the log without secrets and the app settings.
For an AI assistant
The same in English: paste it together with the log into the AI chat.
mevcore error code: runtime.app_key_missing phase: start / health check diagnosis: APP_KEY is not set platform hint: Laravel cannot run without an encryption key. Add APP_KEY (base64:…) in the Environment tab. platform docs: https://mevcore.com/llms-full.txt
Related errors
All error codes · How to prepare your project for mevcore · llms-full.txt
Can't fix it?
Message support with the error code: we will tell you what to change in the project or settings.