Description of the issue: Brave could not be started at all after enabling the #enable-process-isolation-ui flag and toggle it on in the settings.
How can this issue be reproduced?
#enable-process-isolation-ui flagbrave://settings/systemBrave Version( check About Brave): 1.91.175 (Valid of 1.92.134 !!)
Ref. note - Brave Search (Answer with AI) result:
The #enable-process-isolation-ui flag in Brave Browser (and Chromium) is a security feature designed to mitigate risks from local malware and sophisticated attacks by further isolating browser processes.
This flag enables an initial version of “process isolation,” a mitigation technique that blocks certain kinds of local malware from interacting with the browser. It works by enforcing stricter boundaries between the browser’s internal processes, making it harder for malicious software running on the same operating system to inject code, steal data, or manipulate the browser’s memory.
Security Goal: It specifically targets threats where malware on the user’s device attempts to compromise the browser process itself, rather than just attacks originating from malicious websites.
Implementation: It builds upon existing “Site Isolation” (which separates websites into different processes) by adding another layer of defense at the operating system level.
According to Chromium security updates, this feature was implemented as an initial version and is available behind the #enable-process-isolation-ui flag. It represents an ongoing effort to harden the browser architecture against evolving threats, including those aided by AI vulnerability discovery.
Looks like it’s set to Disabled in Brave so there’s probably some reason for that. I can ask what that rationale is but its important to remember that 99% of those flags are inherited from upstream, not something we implement and I cannot guarantee it’s something we will fix. Additionally, any flags in there, as it states at the top of the page, are experimental in nature and enabling them may cause issues (such as the browser crashing):
For now I would simply go ahead and disable the flag.
It looks like the issue in now in Brave Stable (1.93) – not behind an experimental flag, right there in Chromium 151 Group Policy.
Thanks for pointing me in the right direction! After an entire month of being unable to launch Brave at all, I finally managed to get it working again. I’ve already switched to another browser in the meantime because of this issue, but at least Brave is able to start now.
