11.6 will not allow iTunes Store from Music or the App Store. Both come up blank

You can also boot into Safe Mode which will clear various system caches and it can resolve bizarre problems.

Hold Shift key while powering on and keep holding it. Let go to login but then immediately hold Shift again. Keep holding Shift until you reach the desktop. You might see two different login prompts depending on your Mac and if you enabled disk encryption or not. Just keep holding Shift only letting go to login and quickly hold it again after you press Return to login. Once you reach the Desktop you will notice the dock background looks different. This is because a generic video driver is loaded. Safe mode won't load any extensions, add-ons, etc. and only loads the bare minimum of drivers. It typically takes longer to boot into Safe mode and that is normal.

Give it a minute or two after you reach the desktop then simply shutdown and restart normally.

Test out your App Store and Music Store.

Olddogphoto wrote:

I just upgraded to this from the previous Big Sur version and these stores do not come up with anything but blank screens. Also, Podcasts Browse takes many, many tries to connect. Anyone else having this issue? Any fixes? Thanks.

See if there is anything here:

If you can't connect to the App Store, iTunes Store, or other ...

When your computer connects to your network on WiFi or wired, it makes a DHCP request and the DHCP server will assign your computer an IP address. Along with the DHCP response, the DNS server(s) are provided. DNS servers are like an Internet phonebook that resolve hostnames to Internet IP addresses. [ apple.com to 17.253.144.10 ]. When you go to apple.com the DNS server looks up the IP address, 17.253.144.10, and returns it to the browser behind the scenes. The browser then loads the webpage.

In most home environments, the router connects to the Internet Service Provider to obtain an IP address and also receives the ISP's DNS settings. The router then supplies your computers and devices internal IP addresses and provides the routers IP address to act as the DNS server for your home computers and devices. The router, in most cases, will cache some of the DNS queries and forward external queries up the DNS chain to the ISP who then forwards to their DNS hosts all the way up to the root Internet DNS servers if necessary.

A blank window may indicate a DNS problem most likely with your ISP's DNS servers. Most ISPs do a horrible job with DNS but it goes beyond being slow and problematic. Some ISPs spy on your DNS queries and may even redirect your queries, etc.

There are several public DNS providers who provide high quality DNS services and it is easy to trouble-shoot a DNS problem as you can override the routers provided DNS on a single computer / device such as your Mac. You can merely input one of these public DNS servers and your Mac will use that service instead of the one coming from your ISP. It is important to note that sometimes even these public DNS services have an outage. You can input more than one DNS server from different providers on your Mac and if one DNS server fails it will rollover to the next one. Most DNS providers provide two servers for this very reason.

Try this: System Preferences -> Network -> (Highlight Wi-Fi or Ethernet or whatever the top most entry that has a green dot) -> Advanced button -> DNS Tab.

You will see a grayed out DNS server listed. That's the one coming from your router. You can click the + button and add one or more of the following public DNS providers to override the router supplied DNS server.

Provider	    Primary DNS	    Secondary DNS
------------------------------------------------
Google	        8.8.8.8	        8.8.4.4
Quad9	        9.9.9.9	        149.112.112.112
OpenDNS Home	208.67.222.222	208.67.220.220
Cloudflare	    1.1.1.1	        1.0.0.1
CleanBrowsing	185.228.168.9	185.228.169.9
Alternate DNS	76.76.19.19	    76.223.122.150
AdGuard DNS	    94.140.14.14	94.140.15.15

Click OK. Then open Terminal and issue these commands to flush the DNS and reset the mDNS Responder on the Mac.

sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

Enter your admin password and press Return. There is no need to reboot.

Test out your App Store and Music Store.

If this works, it would be recommended to configure the DNS servers on your router so all your devices receive the same public DNS servers you defined on the router. Then reboot those devices to obtain the new DNS settings from the router. This is recommended as a best practice due to the horrible DNS implementation provided by most residential Internet Service Providers.

Advanced: The next level of fun is when you setup a Pi-Hole which is a free server you can run on your home network to act as a DNS server which can filter advertising, privacy invading sites, and malware sites. The Pi-Hole will redirect known advertising and privacy invading Internet sites to /dev/null (a digital blackhole). You can run the Pi-Hole software on a NAS or in a server container or on a spare Mac, etc. Or you can buy a cheap Raspberry Pi 3 kit and install the Pi-Hole on it and connect it to your network. Then you put the IP address of the Pi-Hole server as your DNS on your router. Then all the devices connecting to your router send their DNS to the Pi-Hole instead of to the Internet Service Provider. The Pi-Hole will forward DNS queries to the public DNS servers you provide.

When it's not DNS, it could be a bad certificate, bad date/time or corrupted cache files. Safe mode boot flushed the corrupted caches. Glad it worked for you.