Ahout the error for convert unityscript to csharp

Hi, everyone.

Most of our projects were written in unityscript, while the rest were written in C#.Now we're going to convert unityscript code to C# code.

I found the conversion tool that provided by unity official on the https://github.com/Unity-Technologies/unityscript2csharp, download the unitypackage, eventually imported into the project.
Then select tools-> Convert project from UnityScript to C# to start conversion:

Select Convert(verbose logging) in the pop-up window:

After that, the progress bar starts showing the progress of the conversion:

But soon, the problem arose:



I don't know why this problem occurred, and after several attempts at conversion, it failed, just with different Numbers in the error message.

I hope someone can help me solve this problem.
Thank you very much!

Best wishes
Boshi