Hello everyone!

We are running our wiki, mediawiki version 1.42.0-wmf.23 , PHP 8.1.2-1ubuntu2.14 (fpm-fcgi), MariaDB 10.6.16-MariaDB-0ubuntu0.22.04.1-log.

Lately when we import any article that contains citations such as { { cite book } , { { cite journal } } etc.. for example it contains a line like the following "{ { cite book | title = test book } }",

Instead of displaying "test book" it generates a lua error  :

Lua error in Module:Citation/CS1/Configuration at line 2058: attempt to index field '?' (a nil value).

Backtrace:

1. Module:Citation/CS1/Configuration:2058 : in function "init"
2. package.lua:103 :  ?
3. (tail call) :  ?
4. mw.lua:496 : in function "executeModule"
5. mw.lua:768 : in function "loadData"
6. Module:Citation/CS1:4394 : in function "chunk"
7. mw.lua:527 :  ?
8. [C] :  ?

We have been using mediawiki for more than 6 months and this issue only happened in past month.

I appreciate any guidance to identify the problem and solve it.

You need to install Extension:JsonConfig and import also data from Commons or modify module to not use them or disable some of its features.

As I can see in phab:T362754 it is resolved now.

Solved it by configuring the JsonConfig extension to support wikimedia templates  :

Extension:JsonConfig#:~:text=Supporting Wikimedia templates

Thanks a lot Wargo!