Error Loading Unfinished Renderings

Camera model
Raspberry Pi Wide Angle Camera Module

What is the problem?
I often (not always) get this error when I reload the OctoPi web page:

Error Loading Unfinished Renderings
Status: error. Error: INTERNAL SERVER ERROR

What did you already try to solve it?
Not sure what to do

Logs (/var/log/webcamd.log, syslog, dmesg, ... no logs, no support)
octoprint (2).zip (38.4 KB)

Additional information about your setup (OctoPrint version, OctoPi version, ...)

OctoPrint 1.5.3
Python 3.7.3
OctoPi 0.18.0

So, I have the camera set for 2692x1944 pixels, and the Pi cannot render that. So I have it 'disabled' via setting 'Path to FFMPEG' as: /bogus//usr/bin/ffmpeg
And, of course, I'd get an error at the end of the print that it failed to render the timelapse.
Then I just download the images and render on my PC. Later do post-processing to zoom into the items I want to show.
All this used to work without issue. But now, probably due to an update, I am getting this error whenever I refresh the page (but not all the time):

Error Loading Unfinished Renderings
Status: error. Error: INTERNAL SERVER ERROR

The things that concern me on this is:

  1. I never received these errors before
  2. The Internal Server Error : Could this mean something worse?

So:
A) Is there a better way to prevent timelapse renderings?
B) Is there a way to turn off this "Error Loading Unfinished Renderings"?
C) Is "Internal Server Error" an indication of some other problem?

Thank you.

I don't know a reason why it shouldn't. It's rendered without hardware acceleration so the resolution shouldn't matter.
Maybe it takes a bit longer - but you could render it with more than one thread to speed it up.

If the rendering with the correct ffmpeg path still fails please post a log of that so we can look into that.

I ran into rendering issues a while back at this resolution and posted a topic on it. I was informed the Pi did not have enough memory to render images that large.

I see. I did not expect that.
Did you try it with mpeg2video codec? Maybe it works with less memory.

Of course you could use swap to "enlarge" your memory but that would wear your sd card out pretty fast at the need file size.

Sorry but I can't really answer your questions from op

Have you checked to see if the sd card is full in the pi?
Unless you are manually deleting the images after you copy them to render, they are just sitting on the Pi's SD card taking up space

Yup. Download and delete. It's a 64GB SD Card and currently over 48GB free on it (at the moment) with just a few short timelapse images (about 3,500 files). But I get this error even if there are no timelapse images on the SD Card.
/home/pi/.octoprint/timelapse/tmp/