I have noticed that servers in my SharePoint 2013 farm are showing statuses like 'Installation Required' or 'Upgrade Blocked'.
When you install the SharePoint (CU) updates on one of SP server, we see the Installation required and upgrade blocked in the status of servers under the system settings in CA.
Installation Required: The server still not yet installed with the same CU that already installed in other servers in the farm.
Upgrade Blocked : The server is blocked from upgrade as they are on latest CU than other servers in the Farm. Current Server is installed with latest CU and it will remained blocked until all the other SP servers in the farm are installed with the same version.
Performing an upgrade to SharePoint 2016 is relatively straight forward, but is not as easy as upgrading, say, Microsoft Office. There are some considerations which must be taken into account before performing an upgrade. Per my test, I cannot open the exiting file after add the file extension in the Blocked File Types list. Try to clear the browser cache and check again. Then go to Central Administration-Security-Define Blocked File Types, add the file type in the list and check again. SharePoint Server 2013 also provides new and enhanced tools for supporting the upgrade process, such as the site collection health checker and evaluation site collections: Site collection health checker Site collection owners or administrators can use the site collection health checker to detect issues with their site collections and address.
Sharepoint 2013 Upgrade Blocked Browser
Sharepoint 2013 Upgrade Blocked Flash Player
Sharepoint Upgrade Database
Use fiddler and netmon for blocked ports Make sure your app domain works fine. Make sure App Management Service and Microsoft SharePoint Foundation Subscription Settings Service is started on your server. Make sure App Management Service Application and Microsoft SharePoint Foundation Subscription Settings Service Application is started. Bottom line is you would never need SharePoint 2010 environment to test SharePoint 2010 functionality once you built new SharePoint 2013 farm or upgrade to SharePoint 2013. To create the new SharePoint 2010 site collection in SharePoint 2013 environment, Microsoft provides new option to choose “SharePoint 2010 Experience” on the site.