ActivityRepairTool.jar is not repairing a corrupted multisport fit file properly

Hi, did a triathlon activity recently using Garmin Fenix 6.

The sync with Connect was failing, so I download the fit file and noticed it was corrupted when trying to import it manually to Garmin Connect Web.

Then I used ActivityRepairTool.jar to repair the file and I was able to import it on Garmin Connect Web. However, the whiole activity was imported just as "swimming".

Any idea on how I could repair it properly?

Here's the fit file:

2024-10-19-08-06-37.fit.zip

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Ben FIT 1 month ago +1 verified

The Activity Repair Tool repairs files using very broad stokes. It is meant to work every time, your the repaired file was able to upload to Connect, but the results are sometimes not as robust as you want…

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+1 Ben FIT 1 month ago

The Activity Repair Tool repairs files using very broad stokes. It is meant to work every time, your the repaired file was able to upload to Connect, but the results are sometimes not as robust as you want them to be.

What I did was, I converted the FIT file to a CSV, deleted the store-n-forward HR data at the end of the file, and then converted the file back to a FIT file. The attached file uploads to Connect as a multi-sport file. There was nothing obviously wrong with the the store-n-forward HR data at the end of the file. The plan was to delete messages from the bottom up in the CSV and then convert the CSV back to a FIT file until the file would upload to Connect. The store-n-forward HR data just happened to be the last thing in the file. There was probably one bad value in the five plus hours of data.

2024-10-19-08-06-37-fixed.fit

0 marciomacedo 1 month ago in reply to Ben FIT

That worked nice.

Thank you for the detailed explanation on how to fix it!

0 Alan 1 month ago

I have fixed your file with my FIT repair tool. The fixed file is attached.

Read 40,522 records, 987,806 bytes

2024-10-19-08-06-37_fixed1.zip

0 9811827 1 month ago in reply to Alan

> my FIT repair tool

Hi, is the source code available?

It looks like it does exactly what I tried (and failed) to achieve: it is able to modify just a few bytes and the checksum instead of rewriting the whole file. I'd like to know, how it's done.

0 Alan 1 month ago in reply to 9811827

Sorry but the source codes are not available. If you want to try by yourself, you can search for "DataNumen FIT Repair" online.

If you have corrupt files, you can send them to me and I will repair with the tool for you for free.

0 9811827 1 month ago in reply to Alan

I don't have any corrupted files, I want to create my own FIT editor for modifying only specific fields/messages, leaving the rest of the file untouched. It looks like your tool can do that, and I'd like to know how.

Do you use Garmin's SDK (and for what language, if so)? Or have you implemented FIT reading/writing from scratch yourself?

0 Alan 1 month ago in reply to 9811827

From scratch, and based on the FIT protocol, I write the raw file directly, as the SDK does not provide many controls on the raw file directly.