Hi Roger, Totally agree - I've seen similar 'mistakes'. If this doesn't work properly, then it's a positive menace as it will lead the novice users I presume it's aimed at seriously astray. Avoid!

So are the clips actually 47.952i? Make a project in that format and copy the bin into it. What happens then when you try to change speed?

I'd not seen this online tool before. Very neat! I can confirm TrevorA's diagnosis. I exported an ALE from a 25p project, converted it to .csv using the online tool, modified the .csv in Numbers, then converted the new .csv back to ALE in the online tool. My first go produced the error described. A quick look at the ALE (in Text Edit) showed

Interesting. Sounds like we have a bug to report...

I've seen this happen if the clips have either Motion Adapters or Timewarp effects applied. Is that the case for you?

Agreed re Consolidate. Absolutely no need to Transcode if the codec allows .

Just an idea: I notice you're running on Mojave, which was the last Mac OS to have a 'proper' QT infrastructure. But you've got a relatively new version of Media Composer installed, which would normally be on a later Mac OS. I checked the Version Matrix, and your combo is ok, but I just wonder if the MC version isn't totally 'happy'

I link-then-transcode. Background processing generally works OK for me if I use an external Mac-format drive. I get the not-linking problem if I use ExFat drives, although restarting Avid normally cures it. I often find targetting the system drive fails with a 'System Error -5000' which I think means the B/G process doesn't have permission

Unfortunately you've hit one of the limitations of the way Avid's effects system works. The workaround for this is a bit cumbersome... First you need to make a Video Mixdown of the foreground image of the bird (disable the b/g on V1, mark in & out around the bird on V2 then Timeline menu/video Mixdown). Put the mixdown on V3 in your timeline

AFAIK this isn't a known bug or limitation of your version of Media Composer. So there's something peculiar/unusual happening. I presume this has worked OK in the past on your system? Have you tried the standard troubleshooting measures of creating a new User Setting, and a new Project?