Die 1A1j... ist eine Adresse deiner Wallet nehme ich an. Dann könnte man child-pays-for-parent machen und die Transaktion durchkriegen.
Kostet aber zur Zeit mindestens 0,00856 BTC ( 2140 Bytes a 400 Satoshi pro Byte )
Hast du noch so viel in deiner Wallet?

Zur Einstiegsfrage: Auch das Sync muss nicht durchlaufen. Core installieren, wallet.dat ablegen, keys extrahieren. Fertig. (ggf. in anderer Wallet importieren)

Aber ich glaube, das war gar nicht die Frage sondern es geht "nur" um die hängende Transaktion.

Zum Versenden der wallet.dat: Alles richtig. Niemals versenden - schon gar nicht an Fremde.
Aber: Was, wenn auf der Wallet nur noch "Kleingeld" liegt, was man zwar gern wieder hätte aber eben selbst nicht in der Lage ist, es zu retten und man diese Adressen auch später nicht mehr nutzen will? Warum dann nicht an ein hilfsbereites Forenmitglied (im besten Fall mit gutem Trust und vielen Beiträgen) schicken?!
Auch ich habe schon eine Wallet.dat eines Forenmitgliedes bekommen (nachdem ich mehrmals betont habe, dass man sie NICHT an mich versenden sollte).

Wichtig ist das BEWUSSTSEIN, dass man seine Geldbörse einem Fremden in die Hand drückt, der auch damit abhauen kann. Wenn man das WEISS und wenn es nur um Geld geht, dass man schon als verloren abgeschrieben hat, spricht aus meiner Sicht nichts dagegen.
Aber abschließend: Ja, lieber einmal mehr gesagt: NIE DIE WALLET.DAT versenden!

Right click the transaction in the transactions list and choose "Abandon transaction". Then he can resend the Bitcoin but this time include a much higher fee. In Bitcoin Core, you can set your fee by clicking the "Choose" button next to where it says "Transaction fee" on the send page. Then choose the option for "Recommended" and move the slider all the way to the right where it says "fast". Note that in order for the fee estimation to work Bitcoin Core must have been running for a while.

My first question do you know what does your friend use a wallet when He deposited bitcoin to you?
I used and copy paste your transaction id at https://live.blockcypher.com/ but it appears no transaction found.
I think there's something lacking in the wallet that your friends used it.

Wait, is that the transaction size? (Just googled it, and it translates to Total Transaction Size.) If it is, then it's huge amount of inputs, man. It's about 2.5kb transaction which requires at least 0.002BTC as fees. In this case, there is nothing to be done, either it gets confirmed (if you are lucky), or it gets dropped from the network (getting back to his balance).

what did you tell them?

They just told me that it is my problem with loosing deposits. BTC withdrawals also stopped working for me today.

FOR all who have deposits not creditedto their account :

Idk if it is because I chatted with QQ ( ill explain ) that I got mycoins back,

To chat with QQ customer service :

You will need to use google translate to communicate in chineese, ( I talk french and it was translating better than english to chineese )

So QQ is a chat like MSN messenger or ICQ, you can download an english version here : http://www.imqq.com

Afterwards, go onto Bter chineese site ( go up right of the website and change language to chineese )

On the bottom right you will see they offer QQ customer servicewith numbersassigned to them,

In QQ chat software , add these numbers to your friend list :

Customer ① QQ: 930670188
Customer ② QQ: 930625188
Customer ③ QQ: 417677728
Customer ④ QQ: 1091544692
Customer ⑤ QQ: 2795309276
Customer ⑥ QQ: 2753561485

They will get online in China daytime, try to make yourself understood by being simple

At the end of my chat session, I`ve been told he understood and to wait patiently. Like I said i`m not even shure its QQ that made my coins reappear but it did... I also made an e-mail entirely in Chineese but I got no response so my guess is that : YES QQ  did it, but never told me they have.....

So good luck everybody
I hope you guys get your money back too
(dont forget when yu translate something to chineese, retranslate it into english first to see if it makes sense hehe )

Please post some news! and tell us if this helped you! Donations always appreciated XD

listen=1
daemon=1
server=1
rpcuser=name
rpcpassword=password
rpcallowip=10.1.1.*
rpcport=12543
port=12454
addnode=5.249.152.159:12454
addnode=121.215.156.245

cgminer --scrypt -o 127.0.0.1:12543 -u name -p password