Mac OSX hides the library folder by default.
What are your computer's specs? (CPU, RAM, GPU, etc.)
What exact version of AE do you have (down to the last decimal)?
I have an iMac running OS X 10.9.5 with a 3.4 Ghz i7 processor and 32GB 1600 MHz DDR3 RAM. AE that I downloaded this morning is 188.8.131.52.
There is no Quicktime folder in my Library/ folder. It goes from PubSub/ to Receipts/. I do, however, have Quicktime 10.3 and 7.6.6 installed.
I do, however, have Quicktime 10.3 and 7.6.6 installed.
That might be a problem. 7 is good. 10 is bad. Can you get rid of 10?
That's Yosemite, right? They've hidden the Library folder in Yosemite. I don't know how to make it visible, but others do.
Once visible, You can move the QTX into a new folder, renamed to something you like but the OS won't recognize: think "fluffy", "claire", "carbuerator", etc. After that, your machine should default to QT7.x.
Yeah -- that folder just isn't there. It's not hidden; it doesn't exist. The Library folder was hidden, but I found the switch to turn it back on.
I tried to delete Quicktime itself just now and was told that the OS absolutely needed it.
If it was hidden, you're looking at the Library folder within your user home folder. This is not the folder you are looking for. You want to look in the /Library folder which is at the root of your boot drive. That is where you might (or might not) find the DVCProHD files.
If you want to try re-installing QuickTime 7, you can find the installers here.
There is no reason to uninstall QuickTime X as the APIs are completely different, so when the QT32Server task accesses QuickTime, it will only ever find QuickTime 7.