[Users] installation error: mailbox incomplete

[Charles Blair]

   I am trying to install claws-mail version 3.8.1
on a debian linux system.  I had previously been
using version 3.7.6 on another machine.

   When I start claws-mail I get the message

"... detected a configured mailbox, but it is
incomplete.  It is possibly due to a failing
IMAP account.  Use `Rebuild folder tree...' "
[I do use imap to receive mail.]

   When I click on the top folder (the only one
displayed on the left side of the screen), I
see choices including "Rebuild folder tree".
When I select that, it asks if I want to
continue.  I click "Yes" but nothing happens.

     I am using the same installation information
as on the older machine.

    I have tried deleting and reinstalling
claws-mail.  When I run it the first time, the
warnings

   failed to open /usr/etc/skel/.claws-mail

   /root/.claws-mail/clawsrc:  fopen: No such file

are displayed, but then "Welcome to Claws Mail"
appears.