When you are using the Free Trial version, there are some limitations: the converted videos are black and white /grayscale desturated and the Batch mode won't work and some other minor limitations. Once you buy the Pro license and import the e-mailed license file from Help menu choice Import License File, that instantly upgrades the version to Pro and there are no limitations after that.
The Windows version at first time use of BVideoconverter 2.0 will ask to click at the executable of a few free helper programs for later convienience of use, if you don't have them or similar you want to connect to those menu choices, you can just click e.g. Notepad as a place holder until you have installed them and want to do the setup again by starting the function again by reseting the setting from BVideoconverter's settings menu, and you don't have to browse and click the executable, instead you can first place the helper program's icon on the Desktop and then in BVideoconverter click that function reset in the settings menu and click the desktop icon of the helper programs.
Probably in next update this function will be moved completely to the settings menu.
In BVideoconverter 2.0 Linux version there is not that function in the first start and not in the settings menu since there is no need for that. Instead you can anytime you want just open the Apt repo and download the bvchelpers.sh, allow it to run as a program and run it or if you installed from Apt repo's bvcinst.sh originally, that has already done everything needed for you and you don't need any further installation actions , just to buy the Pro license and from arriving e-mail save it to an easy place to find and from BVideoconverter's Help menu choose Import License File and choose the license file where you saved it, and you have done all, it is now Upgraded to Pro and you can start using all the Pro features.