failed to read data from plugin storage file

Hello,

We are being facing a periodical issue with storage file:

```
2019-02-01 05:32:25 +0000 [error]: [windows_eventlog] failed to read data from plugin storage file path="./tmp/storage.json" error_class=Yajl::ParseError error="lexical error: invalid char in json text.\n (right here) ------^\n"
2019-02-01 05:32:25 +0000 [error]: config error file="C:/opt/td-agent/etc/td-agent/td-agent.conf" error_class=Fluent::ConfigError error="Unexpected error: failed to read data from plugin storage file: './tmp/storage.json'"
```
As workaround temp storage is removed and fluent is restarted then.

Config:

```

@type windows_eventlog
@id windows_eventlog
channels application,system
tag sys.raw
read_interval 2

@type local # @type local is the default.
persistent true # default is true. Set to false to use in-memory storage.
path ./tmp/storage.json # This is required when persistent is true.
# Or, please consider using section's `root_dir` parameter.

```

Is there any ideas?
System: Windows Core 2016