Can you post your entire template line here?
I'm not a coder too and after reading many posts I ended up with this template that I can live with:
Code:
{author_sort:.20s:sublist(0,1,&)}/{author_sort:.28s:sublist(0,1,&)}{title:re(\,,_)|--|}/{author_sort:.28s:sublist(0,1,&)}{pubdate:| (|)}{series:.20s| [|}{series_index:0>2s|-|]}{title:.50:re(\,,_)|--|}
Outputs:
Author Sort/Author Sort--Title/Author Sort [Series-03]--Title
Real file name :
Livingstone,_John_Doe_(2019)_[My_series_title_with-01]--The_Working_Title__in_Progress.epub
You can see that I use an output with folders and a variation on the series punctuation.
Also test output into a short path folder (A folder directly at the root drive) to avoid issues caused by long file names being too shortened (maybe avoid the second author's name can be useful to keep the title name!.
Related post:
https://www.mobileread.com/forums/sh...d.php?t=323263
Note: Maybe you should create a different topic on the "populate a custom field from a name template"