J4 DB to replace J5 DB

[antonios]

Hi,
I'd need to reinstall the 5.2.2 joomla framework from scratch, meaning I'd create a brand new empty site with J5.2.2
is it ok to replace the newly created DB with J5 with a DB coming from J4.4.9 back-up?

[pe7er]

Why would you want to create a Joomla 5 website with a Joomla 4.4.9 database backup?
Would you like to re-use your own data?

There are some database changes from Joomla 4.4.9 to Joomla 5.2.2:
https://github.com/joomla/joomla-cms/tr ... ates/mysql

If you want to re-use your 4.4.9 database with Joomla 5.2.2, you have to convert the database to Joomla 5.2.2 using those SQL scripts.

[antonios]

Hi
I already converted the J4 website to a J5 website, however there seem to be some file path that is not correct for some reason, which prevents the webpage to be displayed, so I was suggested to do a full (re)install of an empty website and then copy the backed up DB in the empty one... but I didn't know whether there had been changes in the DB structure, so I should probably work again from J4 forward, as you suggest

[Per Yngve Berg]

Joomla Updater Component -> Reinstall Core Files.

[antonios]

Joomla Updater Component -> Reinstall Core Files.

I did, but I get exactly the same problem ... as per this post: viewtopic.php?f=815&t=1013716#p3736426
Now I am trying to restart from a blank j5 site and import the j5 DB of the site which didn't allow me to correctly load the front page

[antonios]

Update:

I looked for the string "custom" within the DATABASE of the website that gives me that error page, and I found that the _modules table has the string "custom" as a value in the "module" column of some of the rows, not all
All the other rows have the "mod_custom" string as a value or some other "mod_*" value.
I changed the value "custom" string to "mod_custom" and now the home page is visible again.

So the question how was it possible for this to happen? This apparently happened either during the update from J4 to J5 or right after. And more importantly how to prevent this from happening again!!!
Has anyone ever experienced a similar thing?