"not a valid win32 application" with rtools40-x86_65.exe on Windows 10

Hi, Jeroen et al.:

On Thu, Apr 30, 2020 at 6:38 AM Spencer Graves
<spencer.graves at prodsyse.com> wrote:

Hello, All:


        "00install.out" from "R CMD check Ecfun_0.2-4.tar.gz" includes:


Error:  package or namespace load failed for 'Ecfun':
   .onLoad failed in loadNamespace() for 'rJava', details
    call: inDL(x, as.logical(local), as.logical(now), ...)
    error:  unable to load shared object 'c:/Program
Files/R/R-4.0.0/library/rJava/libs/i386/rJava.dll':
    LoadLibrary failure: ^1 is not a valid win32 application

This is an error in loading the rJava package, so it is not related to
rtools40, and probably inappropriate for this mailing list.

As Simon suggested, you may have to install the 32-bit Java JDK. See
also this faq: https://github.com/r-windows/docs/blob/master/faq.md#how-to-install-rjava-on-windows

????? In fact I had both 32- and 64-bit Java installed but only the 
64-bit was in the path.? I added the 32-bit, but that did not fix the 
problem.? The last 2.5 lines in the section "How to install rJava on 
Windows?" to which you referred me reads:


to build rJava from source, you need the --merge-multiarch flag:

install.packages('rJava', type = 'source', INSTALL_opts='--merge-multiarch')


 ????? When I tried that, I got:


Warning in system("sh ./configure.win") : 'sh' not found


*** ON THE OTHER HAND:? The error message above says 'c:/Program
Files/R/R-4.0.0/library/rJava/libs/i386/rJava.dll':
 ?? LoadLibrary failure: ^1 is not a valid win32 application


 >>>> Is "rJava.dll" a valid win32 application?


 ????? Suggestions?
 ????? Thanks,
 ????? Spencer Graves


p.s.? A similar problem with rJava a month ago was fixed by installed 
64-bit Java.? Now with the upgrade to R 4.0.0 and rtools40, this no 
longer works.