unable to use cdav 1.06 with dolibarr 9 using php 5.4.16 on apache

[c-orazio]

i cannot upgrade the php version of our serrver as they are already many services running, so I was obliged to install version 1.06.
then i get this error : Fatal error: Can't use function return value in write context in /var/www/html/IEFC/dolibarr/htdocs/cdav/class/CardDAVDolibarr.php on line 384
Any chance to fix it?
Thanking you in advance

[jpfox]

I think 1.06 should work.

No chance to correct it. SabreDAV used version is no more compatible with this very old version.

PHP 5.x is unsupported since september 2015 !!
https://www.php.net/eol.php