I was wondering what happened to your case? I'm almost in the same situation. The officer did not accept my Background Check Certificate. They asked an additional and I sent them the normal police certificate along with an explanation about the situation + the response from Korean police saying that this is illegal to obtain. Unfortunately, they again asked for additional! Now they have even added a comment hinting that I somehow must get the one they want! Here is the new message from the officer:I emailed them for clarification and they replied me back. I suggest you contact them directly for clarifications
"Police Certificate: From Korea where the residence period has been six months or longer since the age of 18, provide an original police clearance certificate Please see the attached link as to How to get a police certificate https://www.canada.ca/en/immigration-refugeescitizenship/services/application/medical-police/police-certificates/how.html Please note that Background Check is not the same as a Criminal (Investigation) Records Check from a Korean
National Police Station in Koreea. The police certificate must indicate all records have been searched, including any lapsed records."
Any advice?