It should be fine to go from that to current.

I wasn't able to upgrade from 1.10 to 1.16 (latest).

[01-Apr-2022 21:07:48 UTC] PHP Fatal error: Uncaught TypeError: count(): Argument #1 ($value) must be of type Countable|array, null given in /usr/local/www/osticket/include/upgrader/streams/core/26fd79dc-00c949a6.task.php:115
Stack trace:
#0 /usr/local/www/osticket/include/upgrader/streams/core/26fd79dc-00c949a6.task.php(50): EventEnumRemoval->getQueueLength()
#1 /usr/local/www/osticket/include/upgrader/streams/core/26fd79dc-00c949a6.task.php(29): EventEnumRemoval->queueEvents()
#2 /usr/local/www/osticket/include/upgrader/streams/core/26fd79dc-00c949a6.task.php(21): EventEnumRemoval->do_batch()
#3 /usr/local/www/osticket/include/class.upgrader.php(348): EventEnumRemoval->run()
#4 /usr/local/www/osticket/include/class.upgrader.php(121): StreamUpgrader->doTask()
#5 /usr/local/www/osticket/include/ajax.upgrader.php(35): Upgrader->__call()
#6 /usr/local/www/osticket/include/class.dispatcher.php(145): UpgraderAjaxAPI->upgrade()
#7 /usr/local/www/osticket/include/class.dispatcher.php(38): UrlMatcher->dispatch()
#8 /usr/local/www/osticket/scp/ajax.php(316): Dispatcher->resolve()
#9 {main}
thrown in /usr/local/www/osticket/include/upgrader/streams/core/26fd79dc-00c949a6.task.php on line 115

I'm not sure if this happened due to PHP 8.1 being installed. I think I'll try upgrading to PHP 7 and osTicket 1.15 and later on get to PHP 8.1 and osTicket 1.16.

osTicket does not support PHP 8.1. You would need to downgrade to 8.0

I had the same error and I was upgrading on php v8.0.18 from ost v1.10.4 to v1.16.2. I fixed the error by replacing the line in "include/upgrader/streams/core/26fd79dc-00c949a6.task.php" from

function getQueueLength() {
    return count($this->queue);
}

to

function getQueueLength() {
    if( $this->queue == null ){
        return 0;
    }
    return count($this->queue);
}

After this change the upgrade script was able to complete.

lucentminds Thank you so much lucentminds! I had the same issue (Win Server 2022, php 8.0.21, MariaDB 5.5, OST v1.10.x to v1.16.3. Kept falling over during the upgrade and adding your little snippet worked like a charm.

Hi, thanks this worked also for me !