error occurs when composer installs Laravel:

Failed to decode response: zlib_decode(): data error
Retrying with degraded mode, check https://getcomposer.org/doc/articles/troubleshooting.md#degraded-mode for more info

there is a hint, then in this link: https://getcomposer.org/doc/articles/troubleshooting.md#degraded-mode

then analyzed, there are two situations:
1, the network is not stable, can’t get package from composer to specify a repository; 2, the second reason is more complex, anti-virus software, or ipv6 problems.

Due to some intermittent issues on Travis and other systems, we introduced a degraded network mode which helps Composer finish successfully but disables a few optimizations. This is enabled automatically when an issue is first detected. If you see this issue sporadically you probably don't have to worry (a slow or overloaded network can also cause those time outs), but if it appears repeatedly you might want to look at the options below to identify and resolve it.

If you have been pointed to this page, you want to check a few things:

If you are using ESET antivirus, go in "Advanced Settings" and disable "HTTP-scanner" under "web access protection"
If you are using IPv6, try disabling it. If that solves your issues, get in touch with your ISP or server host, the problem is not at the Packagist level but in the routing rules between you and Packagist (i.e. the internet at large). The best way to get these fixed is raise awareness to the network engineers that have the power to fix it. Take a look at the next section for IPv6 workarounds.

If none of the above helped, please report the error.

means to use anti-virus software what, I win10 directly streaked, with anti-virus function, so I directly re-installed once, it was a network problem.