- Create Module:Test1 and Module:Test2
- Merge Module:Test1 to Module:Test2 using Special:MergeHistory
- Now open Module:Test1, It shows:
The revision #0 of the page named "Module:Test1" does not exist.
This is usually caused by following an outdated history link to a page that has been deleted. Details can be found in the deletion log.
If other extensions are also installed, this can cause more strange error (T72827: [1.24wmf20] Fatal error: Call to a member function getProperty() on a non-object, after completely history merging a page), but merging module is also broken even if no other extensions are installed.