Hello, @Alessio76 and @alopezala I’ve experienced this problem in the past and had it happen again yesterday. My setting is “Production” Update Channel, so maybe that’s why it took me till now to have the problem.
Despite the act of assuming being usually misguided, I’m going to assume the solution to your problem is the same as mine. My problem stemmed from a time-out issue in PHP and FastCGI. The reason I had it happen again was I upgraded to the PHP 7.3 from 7.2 and it had been so long that I forgot what settings I changed in the ~/php7.2/php.ini file, so they needed to be put into the ~/php7.3/php.ini file also. Just set the max_execution_time variable to about 1200.
I had an additional twist this time as opposed to the last time, my Apache file also needed a tweak it didn’t have before.
<IfModule mod_fcgid.c>
FcgidIOTimeout 1200
</IfModule>
After adding that directive to my ~/subdomain.fqdn.com.conf files all went well for the upgrade to NC 16.0.4. I just inserted that directive at the bottom because it needs to be outside of any directory type Apache blocks.
Oh, also I was stuck on step 3 where it wouldn’t re-run the updater from the start, and this snare is solved by deleting a simple file:
Here’s a link to the solution that first saved me when I got into this “Step 3 is currently in process. Please reload this page later.” jam. This time I bookmarked his posted solution to make it easier for me to find again.