Hello Parai & welcome to the Immunet forum, any support issue dealing with possible bugs is taken "very seriously" & are usually dealt with in a timely manner is what I recollect from my experience of using Immunet over the years.
Feel free to start a new topic in the Support (Issues & Defects) section of the forum if you encounter what you may think is a new bug. In fact, we encourage that input from users just to make the product that much better.
Immunet uses a bootstrapper installer that requires an internet connection during the install process so you will get the newest 6.2.4 version, which I would "definitely" recommend you use.
You can download the newest installer by clicking on this link here. https://download.immunet.com/binaries/immunet/bin/ImmunetSetup.exe
Please note: Immunet no longer supports Windows XP or Vista so I hope you're not using one of these older Operating Systems.