Upgrade and lost all my ltc wallet 0 no fille wallet.dat

i do the same i had 2ltc yersterday on litcoin Qt i send 0.3 to a person she receive only 0.1 not confirm so he ask alert key compromised upgrade required , i do yerterday night litecoin.core but this morning in my wallet there is 0.
i try to find my 1.7 ltc but i can t fin the fille wallet.dat on my computer help me please.

help me please

Can you please print screen your wallet here so that we can know what problem

yersterday it was synchro with 2ltc.
i sent 0.1+0.2, arrice first 0.1 not confirm and 0.2 not arrived yet.

so tersterday i upgrade in litecoin core and all was good but with 0 ltc, i lost them.

so today i reinstall old version and 1.7 appareid.

pleas help i m old french and data processing i m not good.

i want my LTC back

Copy the wallet.dat from your old wallet and paste it to your new Litecoin core wallet

i can t find the wallet.dat on my computer