Repository broken after update

After updating to the latest release, I am no longer able to refresh the repository:

root@DietPi:~# apt update
Ign:1 > https://www.mirrorservice.org/sites/raspbian.raspberrypi.org/raspbian > stretch InRelease
Err:2 > https://www.mirrorservice.org/sites/raspbian.raspberrypi.org/raspbian > stretch Release
404 Not Found
Hit:3 > Index of /debian > stretch InRelease
Reading package lists… Done
E: The repository ‘> https://www.mirrorservice.org/sites/raspbian.raspberrypi.org/raspbian > stretch Release’ does not have a Release file.
N: Updating from such a repository can’t be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

Also, dietpi-software does not work anymore:

Welcome to DietPi-Software

[FAILED] DietPi-Software | Connection test: > https://www.mirrorservice.org/sites/raspbian.raspberrypi.org/raspbian
[ INFO ] DietPi-Software | exit_code = 8
[ INFO ] DietPi-Software | VERSION:v6.5 | HW_MODEL:1 | HW_ARCH:1 | DISTRO:4
[ INFO ] DietPi-Software | Log file contents:
Spider mode enabled. Check if remote file exists.
–2018-04-01 03:01:02-- > https://www.mirrorservice.org/sites/raspbian.raspberrypi.org/raspbian
Resolving > http://www.mirrorservice.org > (> http://www.mirrorservice.org> )… 212.219.56.184, 2001:630:341:12::184
Connecting to > http://www.mirrorservice.org > (> http://www.mirrorservice.org> )|212.219.56.184|:443… connected.
HTTP request sent, awaiting response… 404 Not Found
Remote file does not exist – broken link!!!

How to fix this?

I changed my /etc/apt/sources.list, change the line that contains

https://www.mirrorservice.org/sites/raspbian.raspberrypi.org/raspbian

to

https://www.mirrorservice.org/sites/archive.raspbian.org/raspbian/

and it should work.

I don’t know what the long term effect is, but hope it works.

Thanks. Is it safe to keep that change or will it presumably break something in the future? Will dietpi-update work as expected?

Should be fine, a patch in v6.6 will be applied to update sources.list to use the new RPi repo url (Index of /raspbian):
https://github.com/Fourdee/DietPi/issues/1659#issuecomment-377561175