[Launch box / Big Box won't load Event 1000 and 1026 error]

From a programmer viewpoint, when this error occurs "Format of the executable (.exe) or library (.dll) is invalid."  it is because the module is not a .net module or the file is corrupted. Check if you have any sort of trojans or viruses trying to modify your files . 

Also sometimes it happens on 32bits operating system even if the software is developped to run on Any CPU architecture but i dont think it is the problem, may i ask what version of windows do you have ?

 

[LAUNCHBOX DEAD after upgrading to 11.6 -]

upload your log file, if this happened on v11.5 and v11.6 then maybe it is because of pirated license.xml file. Launchbox will exit when populating games playlist if it finds a pirated license