Synthetic Browser Click-path Monitor Crash Pad Process Hanging

[Ryan1233312]

Technologies:
ActiveGates are running RHEL8.10, with plenty of Memory and with the following version of AG:

ActiveGate1.325.24.20251017-232750

Synthetic 1.325.25.20251015-113155

Chrome(-ium)133.0.6943.141

Checked logs - 2025-12-09T11:12:15,213Z ERROR [BM-ModuleDiagnosticsService-1] ModuleDiagnosticsService: DIAGNOSTICS TEST HAS FAILED! BROWSER MONITORING MODULE IS NOT OPERATIONAL! RESTARTING VUC!  

Seeing lots of Process chromium-browser crashed with status "Illegal instruction" in the logs.

It seems sporadic to how/when this happens but the crashpad processes build up continuously until eventually the vuc process/synthetic engine fails. 

[t_pawlak]

Hi,
This looks like the Browser Synthetic engine (VUC) is failing because the bundled Chromium is repeatedly crashing with “Illegal instruction”, and the crashpad processes keep accumulating until the module diagnostics fails and VUC restarts.
“Illegal instruction” typically points to a CPU/virtualization instruction-set mismatch (missing CPU flags / older CPU / hypervisor not exposing required instruction sets). Please verify CPU flags (lscpu, /proc/cpuinfo) and whether the VM exposes modern instruction sets.
Also note that RHEL 8.10 is deprecated for Synthetic-enabled ActiveGate and ActiveGate 1.325 is the last supported version on RHEL/Oracle/Rocky 8; Dynatrace recommends migrating Synthetic-enabled ActiveGate to RHEL 9 / Ubuntu.
Dynatrace ActiveGate 
as u can see in documentation IMO, the workaround is restarting the Synthetic engine/ActiveGate, but the durable fix is moving the private location to a supported OS/host (RHEL9/Ubuntu) and/or CPU platform

[Ryan1233312]

Hi @t_pawlak That is very useful information regarding the potential for CPU/virtualisation instruction-set mismatches. I will review into that further and see if we have any compatibility issues on the CPU or VM level. 

We are looking to try and upgrade further to RHEL 9 but only once we have managed to stabilise RHEL 8.10 and have confidence this issue does not persist.

Will update here further