I refused to open sop: links in Sopcast. Is there anyway to reset it?

Open the following URL:

chrome://settings/handlers

See if it is there so you can reset/change it.

If it is not there try this:

1. Close chrome and kill all processes that have to do with Chrome.
2. Go To %LOCALAPPDATA%GoogleChromeUser Data.
3. Open Local State in a text editor.
4. Search for Protocol or SOP.

If it's not there you can also search in %LOCALAPPDATA%GoogleChromeUser DataDefault and open Preferences in a text editor. Search for Protocol or SOP

Another possibility:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINESOFTWAREPoliciesGoogleChromeURLWhitelist]

"1"="sop://*"

or

"1"="sop:?*"

If none of your protocol handlers work, try turning them on in Chrome.

1. Click the More Actions ( ⋮ ) menu.
2. Click Settings.
3. Click Privacy and security.
4. Click Site Settings.
5. Click Additional permissions.
6. Click Handlers.
7. Click the switch next to Do not allow any site to handle protocols.

If you only need to change a single handler, look for the protocol handler icon on the right side of the address bar:

Click on the icon and select "Allow" or "Manage". Generally, any handler that has been blocked should appear in the Handlers settings window as shown below:

If you are using Windows 10, you can change the default protocol by:

1. Open Settings -> Apps
2. On the left pane select Default apps.
3. On the right pane, scroll down and select "Choose default apps by protocol".
4. Look for the protocol on the list, then click on the current default app (in your case Google Chrome)S select another app among the list of apps to set it as the new default app to open the protocol.