FlexBV does not require installation in the traditional sense
FlexBV is built as a "free standing" binary, it does not require to be installed in to the OS, it is more akin to the original, simpler, easier style of programs that will run directly. This makes it very easy to move it around, upgrade, and remove.

Linux
To unpack and run; 

tar zxvf FlexBV-Rxxx.tar.gz
cd FlexBV-Rxxx
./flexbv

Available command line options; 

./flexbv  [-h] [-V] [-l] [-c <config file>] [-i <intput file>] 
		[-x <width>] [-y <height>] [-z <fontsize>] 
		[-p <dpi>] [-r <renderer>] [-d]
	-h : This help
	-V : Version information
	-l : slow CPU mode, disables AA and other items to try provide more FPS
	-c <config file> : alternative configuration file (default is ~/.config/FlexBV/fbv.conf)
	-i <input file> : board file to load
	-x <width> : Set window width
	-y <height> : Set window height
	-z <pixels> : Set font size
	-p <dpi> : Set the dpi
	-r <renderer> : Set the renderer [ OPENGL1 = 1; OPENGL3 = 2; OPENGLES2 = 3 ]
	-d : Debug mode

If FlexBV seems to momentarily run but then crashes out, try with a different rendering engine, ie, 

./flexbv -r 2

Windows

  1. Extract the downloaded zip archive to a folder of your preference

  2. Run the flexbv.exe binary directly from the newly created folder.

    • Note: When first started, Windows may block the execution and will request that you explicitly permit it to run ( this is the one downside of a freestanding binary package )

  3. If this is the first installation of FlexBV on the system, you will be requested for the licence details that were provided at the time of purchase or from the emailed receipt

    The licence details are case sensitive and there cannot be any spaces at the start or end.

    When the licence details have been entered in correctly, the dialog will go away automatically.

  4. FlexBV has now been successfully set up, ready to load the first boardview.

macOS

  1. Extract the downloaded zip archive to a folder of your preference

  2. Run the flexbv(.app) directly from the newly created folder

    • Note: When first started, macOS may block the execution and will request that you explicitly permit it to run ( this is the one downside of a freestanding binary package )

    • To resolve this go in to Settings->Security and allow FlexBV to Open Anyway

  3. If this is the first installation of FlexBV on the system, you will be requested for the licence details that were provided at the time of purchase or from the emailed receipt

    The licence details are case sensitive and there cannot be any spaces at the start or end.

    When the licence details have been entered in correctly, the dialog will go away automatically.

  4. FlexBV has now been successfully set up, ready to load the first boardview.

  5. FlexBV supports Retina mode resolutions on macOS, if FlexBV does not appear to be using the high resolution, you may need to explicitly make macOS reprocess the Info.plist file from the command line for FlexBV and fbvpdf (schematic viewer)

    /System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -f flexbv.app        
/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -f fbvpdf.app