Error on Cloud Run: “Tried to use SessionInfo before it was initialized” when selecting files

Community Cloud
1

When hosting my Streamlit app on Google Cloud Run, attempts to select or upload a file sometimes fail silently. Inspecting Chrome’s DevTools “Sources” panel reveals an unhandled promise rejection:

Error: Tried to use SessionInfo before it was initialized
    at SessionInfo.get (session_info.ts:45)
    at FileUploader.onChange (file_uploader.tsx:102)
    …

This only occurs in the Cloud Run deployment—on localhost the file picker always works. It appears that after a reconnect (for example, following a brief idle period or network hiccup), Streamlit’s front-end clears its internal SessionInfo and then never re-initializes it before handling the file‐picker promise.

Steps to reproduce:

  1. Deploy a basic Streamlit app with a st.file_uploader to Cloud Run.
  2. Open the app in Chrome and leave it idle for several minutes (or trigger a network reconnect).
  3. Attempt to click the file uploader button.
  4. Observe in DevTools → Console / Sources that an unhandled promise rejection fires with “Tried to use SessionInfo before it was initialized.” The file selection dialog does not appear, and the upload never proceeds.

Expected behavior:
After a reconnect or idle timeout, Streamlit should re‐establish its SessionInfo before handling UI events such as file uploads. The file picker dialog should open reliably, without throwing an error.

Actual behavior:
The front‐end throws an unhandled promise rejection and silently fails to open the file picker. Users must manually reload the page before they can select files again.

2

Did Cloud Run terminate your server process (it leave logs when doing so)? Cloud Run has a switch for that when the service has no new requests for a while.

In this case it would be hard or impossible to “re-establish” a session in server side. The new process could be running a different image, in a clean filesystem, sharing nothing with previous one.