I've had a look on Ancestry now that it's back up again.
I can only make out fragments of it, but enough to get the gist that several years later the marriage entry was amended in the presence of the couple who had married in 1890.
'In entry no 178 in col 2 for Charles read James(?) Arthur(?) and in ?? of the signature(??) ....'.
Then several words I can't read, not helped by 'maker' and 'Bricklayer' running into the margin.
Then (as Wendy has already noted) 'In the presence of James Arthur Fricker & Rosina Jane Fricker', more illegible bits, and the date April 20 1899.
Somewhere in there must be the name or initials of the clergyman making the amendment in the register: perhaps looking to see who was there in 1899 would help in deciphering the name.
It looks like the page isn't lying flat, and so perhaps the right-hand side is out of focus. You may have to get a copy from LMA to find out exactly what the marginal note says.