The "transient HTTP error" is usually due to the www connection failing.

Universe@home has been having some transient hiccups lately where the project Server appears to be overloaded and you can't even get the website to load without either timing out while partially loading or a complete 404 error message (site not found].

Why did you DETACH instead of just leaving things alone to work themselves out?

Has the failing machine been brought up to date with the necessary BOINC upgrade to non-expired SSL status?

... Just my mobile I can't get onto universe. There isn't a newer boinc for that.

BOINC for Android version.18.1 is Recommended Version
https://boinc.berkeley.edu/dl/boinc_7.18.1.apk
If you are not using this version then...
Download using.your.Android device favorite web browser, save to same.device, open download file to install.

I don't see why not. Give it a try and test for yourself.

I have been running BOINC v7.18.1 on Android pretty much since it was released in August. I can connect to it with a standard BOINC Manager, and also with BoincView (a forerunner of BoincTasks, from about 2007. The RPC protocols haven't changed much.)

If the Android client can't communicate with one particular project, that isn't the fault of one particular Manager.

To be horribly picky, the problem with Windows clients recently was with the included data, rather than the protocol in use. Many of us edited or replaced the faulty file long before the full re-bundled package was assembled.

Many of us edited or replaced the faulty file long before the full re-bundled package was assembled.

For my Windows client running under WINE I created a soft link to the file my Linux distribution uses. Is there a way for Windows to have a file that updates automagically that can be linked to in the same way the Linux BOINC certificate file does?

Is there a way for Windows to have a file that updates automagically that can be linked to in the same way the Linux BOINC certificate file does?

We did have a conversation about that, while we were waiting for what eventually became v7.16.20 to emerge. Read from about https://github.com/BOINC/boinc/issues/4544#issuecomment-937558197

The general consensus seemed to be

1) Windows doesn't make it easy to locate a single 'bundle' file which would work with BOINC's implementation of curl.
2) If there is such a file, it might be in a different place on each release of Windows.
3) If Windows did have such a file, it would be the responsibility of Windows to keep it up-to-date. Many BOINC users run BOINC on old, retired, machines - perhaps with an earlier version of the OS (I'm typing this on a Windows 7 machine). Can we rely on Microsoft to keep the certificates updated on older systems?

I updated the out of date one, then tried them both again, now they both work. Just my mobile I can't get onto universe. There isn't a newer boinc for that.

The newest version is only available directly from Berkeley/BOINC.

BOINC for Android version.18.1 is Recommended Version
https://boinc.berkeley.edu/dl/boinc_7.18.1.apk
If you are not using this version then...
Download from above link using.your.Android device favorite web browser, save to same.device, open download file to install.