Virtual mailboxes: errors after renaming a folder

[André Rodier]

Hello,

I have a dovecot server, running fine, on Debian Stretch.

Virtual folders are set up, and works correctly. For instance, I have
Unread, All and Conversations, and everything works fine.

However, when I rename a folder, I have error messages from Dovecot.
For instance, I had a folder INBOX/Bills, which I renamed
INBOX/Invoices. After that, I have these error messages:

> The reported error was “Failed to select mailbox: Backend mailbox 
INBOX/Bills' added by another session. Reopen the virtual mailbox. (for
backend mailbox Search/All) (0.000 + 0.000 secs).”.

How can I avoid these errors, for instance, how can I rebuild the
indexes every night or so?

Kind regards,
André