When generating files and default language is English then file [project].en-US.xml gets generated fine.
When default language is Hebrew then [project].he-IL does not get generated.
Note that you need to translate the English language file to your own language (e.g. hebrew.he-IL.xml) and put it under the correct folder (i.e. C:\Users\<user>\AppData\Roaming\PHPMaker2026\languages), read Making Language Files.
Hebrew works fine. I am familiar with adding another language and have done so in 2023, 2025 and 2026.
The part not working correctly is the generated xml if I have a project named
cowabanga and I change the menu then the generated file cowabanga.en-US.xml gets genarted, yaaaay.
If default language is not English, if it is for example Hebrew, then the file cowabanga.he-IL.xml does not get generated 
What I need to do maually then to get side menus to appear is to create in the generated languages folder the file cowabanga.he-IL.xml and copy the content of cowabanga.en-US.xml as it was generated when the projet default language was english.
If you meant you have single language project (i.e. the Multi-language setting unchecked), then just make sure:
- The Default language setting is set to
he-IL, - You have
C:\Users\<user>\AppData\Roaming\PHPMaker2026\language\hebrew.he-IL.xml, - The language ID in the
hebrew.he-IL.xmlishe-IL.
Then it should work.
If you meant you have multiple language project (i.e. the Multi-language setting checked) and the Default language setting is set to he-IL, then make sure you have clicked the "..." button and checked both en-US and he-IL.
I do not rememeber having to create a project file like cowabanga.he-IL.xml for every project in 2025.
I meant the language file that is used for all projects, the default English version is english.en-US.xml. That's why I said hebrew.he-IL.xml in the first post. The file name before the language ID is arbitrary, I thought you wanted to name as cowabanga.he-IL.xml.
As for the language files for project phrases (for table/field captions, etc.), there is no need to create language file yourself. They will be generated automatically according to your selected languages as explained in previous post, just make sure you have correct settings. I have tested the demo project with different language settings and the language files are generated fine.