What would prevent an archaeologist from getting visas to other European countries?

Question

What circumstances would prevent an archaeologist, from Macedonia, from getting visas to other European countries?

Answer 1

Nothing unless he got a criminal record. Maybe he stole some artefacts from sites were he was before.. otherwise I see no reason why he shouldn't get a visa or if his passport has expired then he needs to wait.. to get that renewed as well

Answer 2

Either a criminal record, or a probable risk of you overstaying your visa, or in any way violating your visa status. Depends, the UK and Schengen have different rules.