My fault. A spurious older version of luatex too early in the search path. Became disastrous only after the luatex version in the betas changed at some point in time.
However in search of the problem I stumbled on a few statements invoking a Lua error that can be avoided by safer coding, thus sparing non-programmers a problem.

The error message is:
/tex/texmf-context/scripts/context/lua/mtx-context.lua:1819: attempt to index a nil value (field 'filenames')

originates from:
elseif environment.filenames[1] or getargument("nofile") then
    scripts.context.timed(scripts.context.autoctx)

I suggest to change this to (change highlighted)
elseif environment.filenames and environment.filenames[1] or getargument("nofile") then
    scripts.context.timed(scripts.context.autoctx)

The same applies to lines 1208, 1795, 1802

In line 1188 I recommend interchanging the operands for a more natural order; here the check is already done.
    local list = (name and { name }) or (environment.filenames and environment.filenames[1]) or defaultformats

dr. Hans van der Meer

> On 11 Mar 2019, at 22:53, Hans van der Meer <havdmeer@ziggo.nl> wrote:
> 
> I cannot get ConTeXt working on my other machine though I mimicked everything there from the working one.
> Installed the contextbeta with the script than try to run but this fails. See the output from what has been done and what results. Also attached the .bashrc setup sofar as regarding TeX. These are the same on both machines.
> I am stymied of what happened here or what could be amiss.
> Any pointers to the solution will be very much appreciated.
> 
> dr. Hans van der Meer
>