With later versions of Trixie, there is an incompatibility with Rust and TeamViewer remote desktop software on Pi4 hardware.
If you had upgraded the Kernel using Sudo apt-update, then use the instructions below to downgrade back to a supported Kernel version.
These are all the steps to downgrade the firmware.
VERY IMPORTANT
First do a uname -r to see what kernel is running. It could be 6.18.32, 6.18.33 or 6.18.34. Note which one it is. You’ll need it later.
If the kernel is already at 6.12.75-v8+ (or not on a Pi4 hardware) then there is no reason to downgrade as the system is at the correct version. Simply update to the latest myServer which will lock the Kernel from ever getting upgraded to incompatible versions.
// unhold packages
sudo apt-mark unhold linux-headers-rpi-2712 linux-headers-rpi-v8 linux-image-rpi-2712 linux-image-rpi-v8 rpi-eeprom
// downgrade to kernel 6.12.75
sudo rpi-update 98655d3
answer Y to all questions
// install the 6.12.75 linux images and headers
sudo apt install linux-image-6.12.75+rpt-rpi-v8 linux-image-6.12.75+rpt-rpi-2712
sudo apt install linux-headers-6.12.75+rpt-rpi-v8 linux-headers-6.12.75+rpt-rpi-2712
accept Y (enter)
reboot
after reboot
if uname -r shows 6.12.75-v8+ then
if the original kernel is not 6.18.34 make sure to change the 6.18.34 in the following command to match the old kernel version. it could be 6.18.32 or 6.18.33. You have to remove the correct old kernel files.
sudo apt remove linux-image-6.18.34+rpt-rpi-2712 linux-image-6.18.34+rpt-rpi-v8 linux-headers-6.18.34+rpt-common-rpi linux-headers-6.18.34+rpt-rpi-2712 linux-headers-6.18.34+rpt-rpi-v8 linux-base-6.18.34+rpt-rpi-2712 linux-base-6.18.34+rpt-rpi-v8 linux-base-rpi-2712 linux-base-rpi-v8
finally, rehold the linux images
sudo apt-mark hold linux-headers-rpi-2712 linux-headers-rpi-v8 linux-image-rpi-2712 linux-image-rpi-v8 rpi-eeprom
reboot again
after reboot make sure still shows 6.12.75-v8+
sudo apt install linux-headers-6.12.75+rpt-rpi-v8 linux-headers-6.12.75+rpt-rpi-2712