There are issues in the handling of concurrent accessing/writing the corrections file. A proper solution will require a re-implementation on how the file is accessed, probably through the use of lock files. Anyway, given that each country is handled by a single analyst, a solution can be just to create country specific files where to store the corrections. This of course will work until the same user doesn't have two open windows where he/she works contemporarily...
There are issues in the handling of concurrent accessing/writing the corrections file. A proper solution will require a re-implementation on how the file is accessed, probably through the use of lock files. Anyway, given that each country is handled by a single analyst, a solution can be just to create country specific files where to store the corrections. This of course will work until the same user doesn't have two open windows where he/she works contemporarily...