I have an old intranet site running on 3.6.2 and tried to manually upgrade it to 4.1.1. After moving the files over the site just "spins". I have manually upgraded our sites literally 100 times (connection directly to wp.org does not work so there is no way to do it auto) and have never had this come up. I ended up going up one version at a time - 3.7, 3.8, 3.9, 4.0, 4.1) and this worked but wondering why it didn't take before?

Follow up question: Why can't wordpress recognize my version and then upgrade the DB appropriately?

  • The "rule of thumb" is to upgrade incrementally: 2 major versions at max, each time.
    – birgire
    Apr 18, 2015 at 18:32
  • @birgire - I guess an addendum to my question is, "Why can't wordpress recognize my version and then upgrade the DB appropriately?" - will edit.
    – STing
    Apr 19, 2015 at 4:11

2 Answers 2


As usual, I'm going to say that any number of potential issues can arise depending on your plugins and any customization you may have in your theme etc.

I manage a number of WP sites and I have rarely attempted to upgrade by multiple version at once without doing it one version at a time as you got to work in the end. In the cases where I have done so I noted that the sites themselves were quite small and had a very low number of plugins (plugins that I would consider to be stable and well updated).

While I don't have an exact answer, I can say that you have already found a pretty reliable way to avoid this problem in the future by upgrading one version at a time. I would recommend this method anyway because in the event where there is a certain version that breaks functionality somewhere in your site at least going one by one will be the easiest way to get your site to the most up to date version that functions.


It is not tested that way. When a new version is developed Upgrade is naturally tested from the previous one and not from some random version from the past. While the code may intend to work for multi version upgrade there might be unexpected issues because with all the desire to be backward compatible humans will create bugs and the bigger the version gap is the more likely there will be some bug that will affect you.

The "technical" term for what you have been doing is acquiring "technical debt" which might look like a time saving measure at the point in time in which you avoid the upgrade but tends to end up in tiers when you have to make the upgrade, as usually you are under time pressure at that point and you don't really remember the ins and out of your system and it is hard to understand how the many changes that were introduced during the time will affect your system (theme and plugin compatibility are the easy example).

  • Are all of the same major versions running scripts that look back at the DB upgrades? This isn't a theme issue or incompatible plugin.
    – STing
    Apr 19, 2015 at 17:43
  • as you can see in the function upgrade_all developer.wordpress.org/reference/functions/upgrade_all that does the upgrade, it does an incremental upgrade fron version to version, but as I said in the answer, just because the code was intended to work does not mean it will work if no one had actually tested it. There might be many reasons for the upgrade to fail and it might be very related to what you actually have in the DB (therefor the assumption it is not plugin or theme related is not valid by default) Apr 19, 2015 at 18:26

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