I've got a forum on a Dreamhost shared server; they've deprecated PHP 5, breaking the forum, and I need to upgrade my pre-2.3.5 instance to a mysqli-aware version.
I've read the wiki page with the update process and notes regarding pre- and post-2.3.5 concerns. Can anyone advise regarding upgrading without the admin tools of a running forum? Thanks!
As long as you have access to a server instance with running PHP 5.6.x you can use the MLF-version 2.3.5 as the update target from a lower MLF2-version without any problem. After the update to version 2.3.5 your forum is able to run up to PHP-version 7.2.x. But in respect to the security and bug fixes, new features and to be able to follow the further upgrade path you are encouraged to upgrade to version 2.4.20 from version 2.3.5. You can upgrade the forum directly from 2.3.5 to 2.4.20.
I am not convinced to be able to describe a way to bypass the official upgrade script. The relevant changes to be manually adapted are the changes in the database structure – the scripts can easily be replaced by their new file versions. But not only the table structure has to be altered, there are also several changes for the already existing data. A few columns in a few tables got removed or got replaced by new tables.
In example there is the list of already read entries per registered user. Up to version 2.4 these data are stored in a single column in the userdata table but from this version on we have a dedicated table with one line for every singe entry, read by a certain user. So there's one entry per user and entry instead on entry per user and all entries, read by her/him.
It is everything else than simple to change manually. So, no, there is IMHO no nearly simple way to bypass the forum internal function with the single exception of being able to read and understand the code of the upgrade script and to reproduce all the changes between version 2.3.5 and 2.4.20 manually.