I downloaded an AE template from Envato Elements. When I opened it I got the message that the file had to be converted from a previous Windows version to my current version on a Mac. And that the file would be loaded unchanged. It opened the file, but in the composition window all content shows up blank or just with wireframe borders. Or it wil turn up, but after a minute or so. Preview isn't working at all (it won't start). I save the file in various older versions, just to get rid of code that might have this effect, but that didn't help. I went through all composition in the library and the effect is the same. Content is initially invisible, or just the outside border of the place item is shown or it shows after a long time of appearing to load.
Attached what I mean. The opened file shows just a black frame with those corner lines. When I wait for a minute or show the real content suddenly pops up (or not).
Is this a bug with converted Windows or older AE version files and/or Envato templates?
No, that's not it. I'm working on the latest iMac with M1 chip. These things happen now and so often when I try to open an After Effects file which is is made on an older AE version and on Windows. Like a few that are downloaded form Envato Elements. I first get the message that the file is going to have to be converted from a previous Windows version and that the file will remain unchanged, but once it has opened there seems to be something wrong with it. Content, compositions, graphics... all appears invisible with just the edges of it shown as borders in the corner. While no layers have been set to be hidden by example. Sometimes those elements eventually load again after a few minutes. Previewing is totally undoable. I can move the playhead to another position, that tiny blue loading bar under the composition window grows like it's loading something and the view remains black with sometimes corner lines.
It's like converting from an old Windows file doesn't completely work and adds some code to the project which makes the file damaged somehow and not quite work anymore afterwards.