Hi I am trying to create a dictionary for my kindle. It is quite a large one, and I've splitted into 16 files each of them are around 20mb. While I am trying to generate the dictionary, kindlegen gives me the following error:

Error(prcgen):E21013: Two <idx:entry> tags cannot have the same id. I have checked the script that is generating the dictionary entries and each file individually, there is simply no identical id fields. Plus it says that the error is found in third file, while Info(prcgen):I1003: Parsing file URL: shows the second file. I tried to put the xhtml files in a different directory as well and refer to them in metadata.opf but still I am having the same error

Here is the complete error message:

kindlegen metadata.opf -c2 -verbose -o blator.mobi

 Amazon kindlegen(Linux) V2.9 build 1028-0897292 
 A command line e-book compiler 
 Copyright Amazon.com and its Affiliates 2014 

Info:I9007:option: -c2: Kindle Huffdic compression
Info:I9014:option: -verbose: Verbose output
Info(prcgen):I1047: Added metadata dc:Title        "My Book"
Info(prcgen):I1047: Added metadata dc:Creator      "Me and my crew"
Info(prcgen):I1002: Parsing files  0000143
Info(prcgen):I1003: Parsing file     URL: blat-0.xhtml
Warning(index build):W15008: language not supported. Using default phonetics for spellchecker: english.
Warning(parser8):W26001: Index not supported for enhanced mobi.
Info(prcgen):I1003: Parsing file     URL: blat-1.xhtml
Warning(index build):W15001: inflection rule or rule group too long (max=255). Discarded.
Error(prcgen):E21013: Two <idx:entry> tags cannot have the same id.

Any idea ? Thanks in advance

  • It's impossible to answer this question without seeing the complete error messages and the html sections that they refer to. AFAIK, KindleGen will try to resolve links to other files in the same folder, which might cause this error message, because the linked file will contain the same ids as the calling file.
    – user4665
    Jan 10, 2020 at 12:09
  • @NemoXXX, all right, edited accordingly
    – Kaan E.
    Jan 11, 2020 at 1:29

1 Answer 1


I am not sure why my solution fixed the error message but I simply removed id attribute from idx:entry tag, but I left the id attribute alone in a under idx:entry.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.