Sonic.net

I ran another test of trying to look at messages near the start of my INBOX, but this time with additional logging enabled in the alpine email client. Again when I attempted to get the list of message starting from 1 the list was truncated after about 50 messages and the server closed the connection. Then I quit alpine so I could look at the log. A portion of the log near the end is as follows:

IMAP 13:37:43 5/2 mm_log tcp: Reading SSL data
IMAP 13:37:43 5/2 mm_log tcp: Successfully read SSL data
IMAP 13:37:43 5/2 mm_log tcp: Reading SSL data
IMAP 13:37:43 5/2 mm_log tcp: Successfully read SSL data
IMAP 13:37:43 5/2 mm_notify bye: {imap.sonic.net:993/imap/notls/ssl/user="casner"}INBOX: Internal error occurred. Refer to server log for more information. [2020-05-02 13:37:43]
IMAP 13:37:43 5/2 mm_log tcp: Reading SSL data
IMAP 13:37:43 5/2 mm_log tcp: SSL data read end of file
IMAP 13:37:43 5/2 mm_notify bye: {imap.sonic.net:993/imap/notls/ssl/user="casner"}INBOX: [CLOSED] IMAP connection broken (server response)
IMAP 13:37:43 5/2 mm_notify bye: {imap.sonic.net:993/imap/notls/ssl/user="casner"}INBOX: [CLOSED] IMAP connection lost
IMAP 13:37:43 5/2 mm_log error: [CLOSED] IMAP connection lost

It looks like the message "INBOX: Internal error occurred. Refer to server log for more information." came from Sonic's Dovecot IMAP server. Could you please look at the server log at the indicated time and tell me what it says about the error?