StateManagerDisk silently resets corrupted persisted state

[harsh21234i]

Describe the bug

StateManagerDisk.load_state() catches every deserialization exception and returns None without logging or distinguishing corruption from a missing state file. get_state() then treats the corrupted file as a brand-new state and can later overwrite the persisted data with defaults, causing silent backend state loss.

To Reproduce

import asyncio
import tempfile
from pathlib import Path

from reflex.istate.manager.disk import StateManagerDisk
from reflex.istate.manager.token import StateToken


async def main():
    with tempfile.TemporaryDirectory() as tmp:
        manager = StateManagerDisk()
        manager.__dict__["states_directory"] = Path(tmp)
        token = StateToken(ident="client", cls=int)

        manager.token_path(token).write_bytes(b"not-a-pickle")

        print("load_state:", await manager.load_state(token))
        print("get_state:", await manager.get_state(token))

        await manager.close()


asyncio.run(main())

[linear-code]

ENG-12487

[harsh21234i]

Observed output

load_state: None
get_state: 0

The invalid state file is silently accepted as a missing file. A subsequent state write can replace it, with no warning that persisted state was corrupt or unreadable.

Relevant code:

• reflex/istate/manager/disk.py

• StateManagerDisk.load_state()

Expected behavior

A missing state file should create a new default state, but an existing unreadable or corrupted state file should be surfaced explicitly—for example, with an error log and a dedicated exception or recovery path—instead of silently resetting the backend state.

[harsh21234i]

Additional context

This is distinct from the existing debounced-write reports #6806 and #6839. Those concern newer writes being dropped while a write is queued. This report concerns an existing state file that cannot be deserialized.

I searched open issues for corrupted state, pickle deserialization, and StateManagerDisk.load_state, and did not find an existing report.

A fix should preserve missing-file behavior while making corruption observable and preventing an unreadable persisted state from being silently replaced by defaults.

[harsh21234i]

whats your take @FarhanAliRaza @masenf ? Is it valid?