crashes while rendering

I am currently experiencing serious problems with my latest AE CC license

which is installed on a

late 2013 Macbook Pro Quad-Core Intel Core i7, 16 GB Ram

GPU NVIDIA GeForce GT 750M 2GB Ram.

Mac OS: Big Sur 11.0.1 (20B29)

All project files are stored on a QNAP NAS Server.

The Mac is connected to the QNAP server via

Sonet SOLO 10G Thunderbolt to 10gb eathernet port

(read/write performance around 500 gb/sec)

When rendering the 1.2 min Full HD movie the allocated AE cache in my library 1TB SSD is overflowing so drastcally und fast that I get the message that the program stoarage is used up followed by a crash, often a serious kernel panic. I tested increasing the cache to up to 180 gb. No help. I tested ousourcing the cache folder to my Server (10gb eathernet). Eventually it would run through a rendering once and then crash. I emtied all the cache partitions within the AE preferences tab before each render. The program created 140 GB of cache files for the relatively short sequence.

I have also attached error messsages that I get after rendering has completed.

I am under the impression that the Update to Big Sur on this fairly old machine in connection with AE is  causing the problems. 

I also tried deinstalling AE and all the prefs related to it and reinstall the license.

no difference.

I am trying hard to keep this setup running until the release of the 16'' M1 MacBookPro before upgrading.

Any input very welcome.

thank you