To run the NIOS Migration Wizard, you may need to use a different version of Java as detailed here.

By default any Linux OS use last version of openjdk that is:

owner@system:~$ java --version
openjdk 21.0.5 2024-10-15
OpenJDK Runtime Environment (build 21.0.5+11-Ubuntu-1ubuntu124.04)
OpenJDK 64-Bit Server VM (build 21.0.5+11-Ubuntu-1ubuntu124.04, mixed mode, sharing)

Install version 8:

owner@system:~$ sudo apt install openjdk-8-jdk

And change version with:

owner@system:~$ sudo update-alternatives --config java

Then select java-8-openjdk-amd64.

owner@system:~$ java -version
openjdk version "1.8.0_432"
OpenJDK Runtime Environment (build 1.8.0_432-8u432-ga~us1-0ubuntu2~24.04-ga)
OpenJDK 64-Bit Server VM (build 25.432-bga, mixed mode)

After that, you can run DIW successfully.