Add punctuation: In the case that your HMA file doesnt open it is highly likely that you do not have the correct software application installed on your PC to view or edit HMA file extensions
A: In the case that your HMA file doesn't open, it is highly likely that you do not have the correct software application installed on your PC to view or edit HMA file extensions.

Add punctuation: The Danish UNESCO schools have worked with that topic for a number of years under the heading of Breaking the Silence During the seminar I couldnt help noticing that it was the representatives of the American continent for whom the topic was the most sensitive whereas the European and the African delegates can speak more objectively and without prejudice about the sins of the past
A: The Danish UNESCO schools have worked with that topic for a number of years under the heading of Breaking the Silence. During the seminar I couldn't help noticing that it was the representatives of the American continent for whom the topic was the most sensitive, whereas the European and the African delegates can speak more objectively and without prejudice about the sins of the past.

Add punctuation: Secondary osteoarthritis is caused by another disease or condition
A:
Secondary osteoarthritis is caused by another disease or condition.