It was quite confusing for me before I figured out that the User Defined Language (UDL) in Notepad++ have 2 different versions i.e. v1 and v2 which are not compatible with each other as well as the UDL XML file used for import/export.
In Notepad++, there is a feature which you can define your own language for syntax highlighting i.e. User Defined Language (UDL). UDL can be exported and imported with XML file. There are a bunch of UDL files available here (include 2 files for ABAP) so you don't need to define everything by yourself.
However, there are two versions of UDL and they are not compatible with each other. So before import a new UDL file, you should check the version first. Here is how to check:
Determine UDL Version of Notepad++Open User Defined Language settings. Depending on your Notepad++ version, this may in the menu Language --> Define your language...
Otherwise, it may be in menu View --> User-Defined Dialogue...
Notice the title bar, if it shows v2... then it is version 2
Otherwise it is version 1.
Determine UDL Version of XML FileXML File of UDL version 2 will have an attribute something like udlVersion="2.1" in UserLang tag.
Otherwise, it is version 1.
Now, you can import the right UDL version into your Notepad++.
Here are my UDL files of both version for ABAP language on GitHub: