Puppeteer or Playwright cannot find or start a browser
A mevcore app hosting error at the “start / health check” stage.
What it means
The browser was not downloaded during the build or lacks system libraries.
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
Use a Dockerfile based on the Puppeteer/Playwright image (ghcr.io/puppeteer/puppeteer, mcr.microsoft.com/playwright), or connect to a remote browser (browserless) through puppeteer.connect.
- 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.
- 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.headless_browser phase: start / health check diagnosis: Puppeteer or Playwright cannot find or start a browser platform hint: The browser was not downloaded during the build or lacks system libraries. Use a Dockerfile based on the Puppeteer/Playwright image (ghcr.io/puppeteer/puppeteer, mcr.microsoft.com/playwright), or connect to a remote browser (browserless) through puppeteer.connect. platform docs: https://mevcore.com/llms-full.txt
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.