Here is working well reading from country table and setting DXCC from Club Log. Please make sure you are using the country table located in the DB folder (SWLCTRY.mdb). Maybe you are using an old country table.
Go to Tools / For experts only and / Open country table and select the one located in the DB folder.
If still have problems download the latest country table here:
https://www.swisslogforwindows.com/Download/Swlctry.zip
Unzip and copy country table in the DB folder, located where you have Swisslog installed.
Best 73