FIT file cannot be loaded into FIT File Repair Tool

I logged a swim on my Forerunner 945 LTE (500, 3x300, 500, 100) but it didn't record one lap as swimming (just rest). I added the distance via a drill log, but would like to get things back to being accurate. In summary, I want to

  1. Convert the 1:51 rest lap to 100yds of freestyle swim
  2. Remove the extra laps/drill at the end

I tried loading the file into FIT File Repair Tool, but it seems to crash after analyzing. Upon reopening, the data was there, but I was unable to save it due to an error stating:

IsolateRestLengthsIntoRestOnlyLaps

Invalid use of Null

What's wrong with my activity file? How can I rectify it? Thanks in advance.

16561067568.zip