I think you need to "HTML escape" your output.

If your json is (relatively) small (<~3.5MB) then change:

Write formatter.Format(json)

With:

Set sc=FormatToString(json,.fsonFormatted)
If $$$ISERR(sc) {
    Write $zconvert(sc,"O","HTML")
} Else {
    Write $zconvert(fsonFormatted,"O","HTML")
}

If your json is potentially big (>~3.5MB), the you have to use FormatToStream() instead of FormatToString() and $zconvert in chunks, see $zconvert documentation.

If you can share your code it would be much easier to help you

It really seems that there is no java executable in the (supposed?) java home directory you specified.

Can you check if the following file exists:

C:\Program Filey\Java\jdk-11\bin\java.exe

Then there may be issues with the java version, maybe not.