# [FAQ] TiKV can't start,the error is “critical-config-check-failed

## Key Words

TiKV, can't start, critical config check failed

## Description

The tikv_stderr.log reports "critical config check failed".

## Contents

If the tikv-server can't start, and there are some logs in the tikv_stderr.log like this:

```log
critical config check failed: storage data dir have been changed, former data dir is ./, current data dir is /data/tidb/tidb-data/tikv-20160, please check if it is expected.
```

We can rename the last_tikv.toml in the TiKV data dir, and try to restart TiKV.

TiKV-Server will check the last_tikv.toml when it start, if this file were in a broken status, it will report config check error and failed to start. The reasons of why this file be broken should like:

* Space issues when this file is being written.
* Change this file manually, but the configurations were set to a wrong name or invalid value.

## Affected Versions

All