Can you follow below to re-install again:
1. install WSL for windows
Note: Windows 10 build version 16215.0 or higher is the recommended operating system version.
ii. After installation has successfully completed, launch Ubuntu 18.04.
iii. Install additional distro packages required for Nios II EDS using the following commands:
a. sudo apt-get update
b. sudo apt install wsl
c. sudo apt install dos2unix
d. sudo apt install make
2. install nios2 eclipse folder
3. download the patch from below KDB: