There’s a problem for all to see: ball trapped between rugby posts? (2-2)

'there's a problem' is the definition.
('uh-oh' is said when sensing a problem)

'for all to see ball trapped between rugby posts?' is the wordplay.
'for all to see' becomes 'u' (universal dvd certificate).
'ball' becomes 'o' (letter resembling a ball).
'trapped between' means one lot of letters goes inside another.
'rugby posts?' becomes 'HH' (rugby goalposts resemble the letter H).
'o' going within 'hh' is 'hoh'.
'u'+'hoh'='UH-OH'