VB.NET Expert for Software License Issue

A few years ago I bought a software for the energy calculation of buildings because I am an engineer, now the software does not allow me to work anymore, because it stops on the initial window where a warning appears that the software license has expired.

The company that produced this software seems to be no longer active, hence my request for assistance.

I analyzed the exe of the software with DiE and it seems to be written in VB.net.
I also have the installation files of the Trial version, which works perfectly, but does not allow you to save your work or print.

Here is what you need to know:
- I can provide you with the installation files to evaluate the program and formulate a quote.
- I do not have access to the source code, only the installation files, but I can easily view the code with the dnSpy program and the code does not appear obfuscated.
- The program works on Windows.

Ideal Skills:
- Proficiency in VB.NET programming
- Experience modifying software
- Knowledge of Windows operating system
- Understanding of software licensing mechanisms
- Technical ability to work with installation files

Note: Freelancers with relevant experience and skills will be given priority.