Error in flashing Jetson XAVIER NX

INFO : CUDA Toolkit for L4T : E: Failed to fetch File has unexpected size (8079 != 7926). Mirror sync in progress? [IP: 443].
I flash the XAVIER NX through sdkmanager,but when I went to the step 3 to install the downloaded files,The error happened and the terminal displayed this,the installation was stopped.I changed the update sources but it didn’t work.Is there anyone who can help me?