The problem is that there appear (graphic/video) glitches/artifacts in opera and chrome browsers like never before.

I guess that is due to the old nvidia video adapter and the driver nouveau.

The system (2006 year - amd athlon, ddr2 4GB) is with built-in Nvidia nForce 430 / GeForce 6150SE (chipset/video adapter) and debian buster (10) latest updates with lxqt/sddm/openbox (LXQt 0.14.1-1, sddm 0.18.0-1, openbox 3.6.1-8 and Qt 5.11.3) on kernel 4.19.0-10-amd64 (4.19.132-1).

All graphical problems with glitches and system freeze, which i suffered for about 2 years, have been resolved after a downgrade of libgl1-mesa-dri.

What i did was the following - i downloaded libgl1-mesa-dri_18.3.6-2+deb10u1_amd64.deb (it is a buster version released 15 Jan 2020), copied the content of usr/lib/x86_64-linux-gnu/dri from the .deb to /usr/lib/x86_64-linux-gnu/dri/ and restarted the system. Everything worked fine - no more nouveau fault messages, glitches/artifacts or system freeze.

The copied files are:

i915_dri.so
i965_dri.so
kms_swrast_dri.so
nouveau_dri.so
nouveau_vieux_dri.so
r200_dri.so
r300_dri.so
r600_dri.so
radeon_dri.so
radeonsi_dri.so
swrast_dri.so
virtio_gpu_dri.so
vmwgfx_dri.so