I was running 4.7.2 (have since upgraded to 4.8.1) and imported an ofx file. The Online Statement Balance line has been put in the wrong place (incorrect date) and whilst it hasn't broken overall balance, I would like to correct or remove it. Is that possible? (I can't select that line).

The OFX file has;
<LEDGERBAL><BALAMT>-1234.56<DTASOF>20180407050000.000[-7:MST]</LEDGERBAL>
So I would have expected it to be entered with that date, but it went in as 19/03 instead.

Unfortunately, there is no UI based function to remove the information. The only foreseen way to adjust that piece of information is by reading the data from an OFX source (file or online which does not make a difference here). Nevertheless, I would try to re-read the file. Start KMyMoney from a console window to see any messages that it prints during the import. Maybe there is something that gives us a bit more information what is causing the problem. If that does not help, the only way is to massage the data in the KMyMoney file. Before we go that route, I suggest you try to re-read and report back.

That worked I re-imported the file and it has now put the entry in the right place.
Seems it was a bug in the import in 4.7.2.

I probably won't be using .ofx import any more as there seems to be a transaction description limit vs .qif.