and see if they can reproduce these errors, Thanks for all this.
The main thing I need to even make a start at debugging the binary is the exact invocation of the tex4ht executable (and t4ht, if it makes that far). I think/hope make4ht will output that with -a debug, but I admit I'm not sure. Any chance you could try to find the invocations, so I can just start from the dvi you previously sent? --thanks, karl.
