This is a tech support question about Vercel blocking my Browser from access a client website protected by Vercel software.
The website I am trying to access recently switched to Vercel Security Checkpoint software without notice to registered users like me. Vercel now blocks my access to their 3rd Party www.Bidfta.com website whenever I use Malwarebytes VPN software with a USA access point for a secure connection.
When I now access the www.bidfta.com website with VPN, I get a Vercel Error Code 99 that says “Failed to verify your browser”. A second line appears that says “Vercel Security Checkpoint iad1::1786066067-xgbMAd3njSvmytaXaxvZKv4GrRYhwMsw”
I cannot tell what is the Vercel website IP address I should use to enable a Malwarebytes VPN IP address exception for Vercel access using dual-tunneling. I experience this same VPN connect problem when I use a “clean” Firefox Browser (no extensions active) and USA VPN connection.
When I disable VPN, I can connect to Bidfta.com and Vercel with no problem and everything seems to work correctly. My VPN access was not blocked on the Bidfta.com website until Vercel Security Checkpoint was recently implemented.
Regarding the error message, I called the website’s customer support department for help and they do not know what to do nor whom I should contact regarding this concern.
I have a fairly standard setup as a client end-user on a Win11 Pro Laptop, I use the latest version of Javascript 64-bit. The Browser I prefer to use is the latest version of Mozilla Firefox Win11 64-bit. My Win11 Pro Laptop also uses the all of the latest Microsoft updates and has Malwarebytes VPN installed.
How can I fix my end-user Win11 Laptop connection with VPN to the Bidfta.com website so I can correctly use VPN access without getting this Error Code 99 “Failed to verify your browser” error?
After additional searching on the Internet, I found the following GitHub summary., but I am unsure if I can do anything on the client side since the problem and coding is with the Vercel Web Application Firewall (WAF)…
Browser Navigation Gets Stuck at Vercel Security Checkpoint
"A “Vercel Security Checkpoint” error code (such as Code 11, Code 99, or Code 705) means Vercel’s Web Application Firewall (WAF) has flagged your browser session or IP address as a potential bot. This blocks the page and prompts a “Failed to verify your browser” challenge. [1, 2, 3, 4, 5]
Common Causes & Fixes
- VPN or Proxy Usage: Privacy VPNs often share IP ranges heavily flagged by automated DDoS mitigations. Disabling your VPN usually resolves Code 99 or Code 705 errors. [1]
- Strict Privacy Browsers / VMs: Browsers like LibreWolf, Tor, or running inside a virtual machine (VM) can strip or alter hardware and WebGL signals. Re-enabling graphics acceleration, turning on WebGL, or switching to a standard host browser fixes Code 11. [1, 2]
- Browser Extensions: Aggressive ad-blockers or script-blockers can interfere with Vercel’s background fingerprinting challenges. Try disabling them temporarily or opening an unmodded incognito window. [1, 2]
- False Positives: Sometimes Vercel’s automated rules misidentify legitimate mobile or desktop traffic. If you manage the site, you can review or adjust settings under the Vercel Project Security Settings. [1, 2, 3, 4]
How to Fix It as a Visitor
- Disable VPN/Proxies: Turn off any active virtual private networks, custom DNS configurations, or strict privacy relays that alter your IP reputation. [1, 2]
- Clear Browser Data: Delete cookies and site data for the specific domain, then reload the page. [1]
- Check Extensions: Turn off ad blockers, script blockers, or privacy extensions (like uBlock Origin or Privacy Badger) that might block Vercel’s challenge script. [1, 2]
- Switch Browsers/Settings: Try opening the site in a clean profile or standard browser, ensuring JavaScript and JIT (Just-In-Time) compilation are enabled. [1, 2, 3]
How to Fix It as a Site Owner
- Disable Attack Mode: Log into your Vercel Dashboard, go to your project settings, navigate to the Security section, and toggle off Attack Challenge Mode if it was falsely triggered. [1]
- Review Firewall Rules: Check your edge firewall configurations for overly aggressive bot rules or misconfigured block lists. [1]
- Contact Support: If the block persists falsely, reach out to Vercel Support to request a manual block override or investigation into edge mitigation logs. [1, 2]