"Send Entire Balance" left the equivalent of the transaction fee on the sender address

[leafcutterant]

MEW 3.11.2.4

When I tried to send the full ETH balance of an address (with the dedicated option "Send Entire Balance"), MEW put my entire balance in the Amount field. This felt wrong because, then, how could the transaction fee be paid? Out of curiosity, I went ahead anyway and pressed send. Nothing happened. Pressed send again. Still no green bar at the bottom. Now I checked Etherscan and the tx was there, and soon confirmed. But it left an ETH amount on the sender address that is equivalent to the transaction fee.

This frustrated me, so I calculated the balance of that address from transaction to transaction, and the blockchain indeed didn't make a calculation mistake. But then it was probably MEW that displayed/detected my balance incorrectly.

What happened? How does "Send Entire Balance" work under the hood?

[wparad]

Can you post the transaction?

[leafcutterant]

@wparad, I won't post my transaction here. Maybe if you give me an address and a PGP key.

But there's no need even for that, just try it. It happened to me again in the last few days. I was using the very latest release (3.11.3.3).

It is not consistent though. I made a similar "send entire balance" transaction today and this time it worked properly. But this was the same 3.11.3.3 version.