I have added this issue to the tracker:
Issue 2212 – Updates check fail because winscp.net certificate cannot be validated
You can vote for it there.

@steliosh: Duplicate post:
Check for Updates fails with error 80092013

Hello.

I have upgraded to the latest version 6.1 build 13674 on Windows 10 22H2 on a corporate network with proxy enabled.

When triggering the option to check for updates I get the following dialogue box

Error checking for application updates

Certificate not trusted
Error:80092012 Chain index: 0, Element Index: 0
Server certificate verification failed: issuer not trusted

Best regards,
Stelios

Sorry, I do not know. Our site certificate is trusted by the default Windows installation. I cannot know what changes did your company made to your Windows installation.

@martin: Sorry, didn't see your reply. Yes this is a corporate managed laptop. Even when I disable my VPN, it still gives me the same error. I currently have the 5.16.4 RC (Build 10069) version of WinSCP.

Thanks. Is that a personal/home computer? Or some corporate-managed one?

@martin: Here is what I get when I do that...

Can you please go to Preferences > Updates > View Statistics, type "update" to the Filter and post the results here?

@martin: It happens everytime I try to check for updates. I has been happening for over a year, but I finally took the time to complain ;) LOL

I have same problem: "Server certificate verification failed: issuer is not trusted"

Thanks for your report. How long does the problem last? Does it still persist?

Every time I try to check for Updates from WinSCP on Windows 10, I get these error...

Certificate not trusted.
Error: 800B0109, Chain index: 0, Element index: -1
Server certificate verification failed: issuer is not trusted

Is there a reason why your cert is not trusted?