So our parallels tools no longer installs on current debian 11 (buster).
The missing linux-header package version can be fixed though and here is how:
After mounting the installation disk via the paralles menu in the vm run:
Code:
mount /dev/cdrom
mkdir -p /tmp/cdrom
cp -R /media/cdrom/* /tmp/cdrom/
cd /tmp/cdrom/
wget 'https://snapshot.debian.org/archive/debian/20211001T101807Z/pool/main/l/linux/linux-headers-5.10.0-9-common_5.10.70-1_all.deb'
wget 'https://snapshot.debian.org/archive/debian/20211001T101807Z/pool/main/l/linux/linux-headers-5.10.0-9-amd64_5.10.70-1_amd64.deb'
dpkg -i linux-headers-5.10.0-9-common_5.10.70-1_all.deb
dpkg -i linux-headers-5.10.0-9-amd64_5.10.70-1_amd64.deb
./install
The snaphost archives luckily contains the right version and it is possible to install. Depending on any conflicts or previous installs of that packages your mileage may vary.