open data/accounts/acc1/msg/f/xxxx: no such file or directory

On a unstable, slow internet connection I was deleting messages in the Inbox. Something may've gotten deleted improperly:

```
Error from server during request for messages: querying messages: parsing message 41544: parsing headers: open data/accounts/acc1/msg/f/41544: no such file or directory
```

The Inbox now won't load up.

How to handle it?