Ok. I've found the culprit, and what a doozy of detective work.
This morning one of our motion designers showed up, I warned him about the farm and he informed me he had a comp that was rendering just fine using .mov files.
This was the holy grail. I opened the comp, and versioned up, then kicked off a command line render. Everything good so far.
I replaced the quicktime file with a different one and the comp refused to render...
The real clue came when I then changed it back to the original file (that worked a second ago) and the comp refused to render.
I exported both the working and the non working comps out as XML to see if there is any differences. They are using all the same settings, only diffference is that the quicktime file was reimported from the server in the non working file.
There were a few cosmetic differences in the files but the offending line is this:
Under the item tag for the quicktime file before the path is a <sppc bdata> tag
In the working file it appears as:
<sspc bdata="000000000000000000000000000000000000000000004d4f6f56000000000000114f0000114f000000a800000019000000000000001900000000001900000030010100000000000000034649454c00010000000000000000000000000000000000000000000000000000000000000000000000000000da8e58860000000c0000000100000000000000000001000000010000000000000000001900000000000800000000000000000000000000000000000000000000000000000000ffffffffffffffff00000001000200000000000078727da400000000000000000000"/>
In the re-imported (non-working comp) it appears as:
<sspc bdata="0000000000000000000000000000000000000000000044585633000000000000114f0000114f000000a800000019000000000000001900000000001900000030010100000000000000034649454c00010000000000000000000000000000000000000000000000000000000000000000000000000000da8e58860000000c0000000100000000000000000001000000010000000000000000001900000000000800000000000000000000000000000000000000000000000000000000ffffffffffffffff00000001000200000000000078727da400000000000000000019"/>
If I swop the tags from the working file to the non working file- it works. Hell I don't event have to swop the whole tag the characters between 44 and 48. Changing "44585633" to "4d4f6f56" let's aerender open and render the file.
So, I created a new project, imported a quicktime file and saved it out as xml. Did a search for the <sppc bdata> tag and changed "44585633" to "4d4f6f56". Hit save. Launched it on the farm via the command line and lo and behold. Rendering.
Now here's the really annoying thing.
The workstation I was building the comp on was AE 16.1.1 - leading me to believe this is an AE version thing... spoilers it's not.
I tried the same trick on a machine running AE 16.1.2 - but it didn't work. Simply replacing part of the <sppc bdata> tag broke the file enough that aerender wouldn't open it. The file still loaded in After effects though.
Here is a breakdown of 3 versions of ae with their codes for the same file:
16.1.1
<sspc bdata="00000000000000000000000000000000000000000000445856330000000000000fa00000094c000002ee00000019000000000000001900000000001900000030010100000000000000034649454c00010000000000000000000000000000000000000000000000000000000000000000000008000000d7db66a40000000c0000000100000000000000000001000000010000000000000000001900000000000800000000000000000000000000000000000000000000000000000000ffffffffffffffff0000000100020000000000008028fc0400000000000000000000"/>
16.1.2
<sspc bdata="00000000000000000000000000000000000000000000536f6c690000000000000fa000000a780000000000000001000000000000025800000000000000000000000000000000000000030000000000000000000000000000000000000000000000000000000000000001000000010000000000000000da87384f0000000c0000000100000000010000000001000000010000000000000000000000000000000000000000000000000000000000000000000000000000000000000000ffffffffffffffff0000000000000000000000000000000001000000000000000000"/>
16.1.3x5
<sspc bdata="000000000000000000000000000000000000000000004d4f6f560000000000000fa00000094c000002ee00000019000000000000001900000000001900000030010100000000000000034649454c00010000000000000000000000000000000000000000000000000000000000000000000008000000d7db66a40000000c0000000100000000000000000001000000010000000000000000001900000000000800000000000000000000000000000000000000000000000000000000ffffffffffffffff0000000100020000000000008028fc0400000000000000000000"/>
Here's the catch. ALL the farm machines write the SAME sspc string - those important middle digits : 4d4f6f56.
But even after updating the workstations to the same version, even with a clean and reinstall of only after effects. They write the digits as: 44585633 - which the farm doesn't accept. Again, I can manually change those digits around and then the farm will be happy but that doesn't get me closer to automated rendering.
I went out on a limb and hoped that the hexadecimal would mean something in normal ascii...(please please please)
44585633 = DXV3
4d4f6f56 = MOoV
...Well that's weird I hear you all say. Yes, that is weird. You might recognize those shortcodes from somewhere. MOov is like OLD SCHOOL quicktime digits. People who use nuke or FFMPEG might have seen them pop up.
But DXV3? I only learned that one two weeks ago. It's the RESOLUME codec, that they use to playback files in real time, think HAP but with a better marketting. The free converter from Resolume , caled alley, is standalone but includes a dvx3 import/export addition that adds that functionality to AE / Premiere. Seems like someone there goofed and it does it a little too aggressively.
That little import/export plugin has been quietly replacing all the metadata of Quicktime files, replacing the friendly "this is a mov" metadata with "this is a dxv3 file". Of resolume, what have you done?
The plugin/codec is installed in Common, which explains why it was persistent through reinstalls of CC (CC Cleaner does not remove third party installs from common)
So in the end, delete the Resolume DxV3 folder from the common\7.0 plugin folder (or alternatively install it across the entire farm) By this point I needed to delete something so au revoir resolume.
What a struggle, and what a lesson in debugging - I'm sure this will be a movie in a few years.
Thanks to Martin for your suggestions, it kept me trying stuff and thanks to Mylennium for showing up. And above all, thank you to the ONE comp that worked despite all the evidence to the contrary. Turns out that was the one motion machine that didn't have the plugin installed. And thanks to HEX to ASCII converters on the internet.
My suggestion to the admins or Adobe staff would be this:
Make the error message describe the problem better.
"File not found" is dead wrong as an error. "File codec "DXV3" not recognized" would have been ideal.
This thread is now closed! Happy friday everyone!