Thanks, I have followed your instructions and I have managed to send half of the coins of address A to address B in the same wallet. The problem is that if I now check address A on Bitcore Blockchain explorer it apparenly contains no coins any more, while the total amount in the wallet is still correct. I have checked all addresses of the wallet on explorer, but the coins which were in address A are nowhere to be found, even though they didn't disappear from the total balance of the wallet. Bitcore Blockchain explorer however still gives me the old rank of that address, so perhaps it does not work properly? Any ideas about this magic occurence?
Enable coin control. You will find that your change went to a new address that you also control. You should also be able to see this new address on the block explorer.
I have checked on block explorer all my listed receiving addresses, but I didn't find the change coins - can there be an unlisted address in wallet?