1.APP Store is in the United States, so we are mostly network problems, we can try to modify DNS to solve, in the Mac we find the "Open Network Preferences" option, as shown in the picture
2. Then we click on the connected network now click the "Advanced" button below
3. In the Open advanced interface we find the DNS column, click to enter
4. Then click the + button at the bottom left of the DNS Settings window to add a new DNS address.
5. Here we enter DNS 114.114.114.114 or 8.8.8.8 then click "OK".
6. Now return to the Network window and click "Apply".
7. Now let's try to open the app Store to download the software to see if it can be downloaded.
8. If the above method tried, or not, you can try this wonderful method. Sometimes we go to the purchased page and we can download it, but most of the time, even though it's installed on the purchased page, the same thing happens.
9. Now we open the "app" in Finr to find the software we just can't download.
10. Then we turn off the app Store and go back to the desktop to find the failed app that we just downloaded and double-click it to see
11. If not, just change the time period and then download it.