Webcalendar php error

We have three one-click installs: wordpress, xoda, and webcalendar. All are PHP programs. Recently I noticed that xoda and webcalendar, which had been working for a long time, were giving PHP errors. I guessed that some upgrade of wordpress had required moving to a newer PHP, which was making these programs ill.

xoda was marked manual installed, so I deleted it, reinstalled it (to version 0.4.9), and reconfigured it to the previous customizations. The PHP errors stopped.

I then tried the automatic upgrade of webcalendar (to 1.2.7) and reconfigured it. It got fewer PHP errors, but still does not work. The current errors are:

Deprecated: Assigning the return value of new by reference is deprecated in /home/cmsb/cmsob.org/applications/webcalendar/login.php on line 18

Warning: Cannot modify header information - headers already sent by (output started at /home/cmsb/cmsob.org/applications/webcalendar/login.php:18) in /home/cmsb/cmsob.org/applications/webcalendar/includes/config.php on line 259

line 18 of login.php is:
$WebCalendar =& new WebCalendar ( FILE );
lines 258-259 of config.php are:
header ( ‘Location: install/index.php?action=mismatch&version=’
. ( empty ( $row ) ? ‘UNKNOWN’ : $row[0] ) );

Web search showed older posts of similar errors but nothing recent and no hints of how to fix it.

We can’t be the only dreamhost user of webcalendar. What do I have to do to get webcalendar working again?