thanks you for your help JuanJGon,
I've deleted all but the geo that crash the app,
few details : crash occurs during preprocessing in IPR
i've moved away all that might come into my mind like : AI lights, adaptive sampling, denoiser, multiproc uploading, nodes connected to mat, export passes, octane transfer attributs,
and i've configured render params to be as default as possible.
You can download it here : https://we.tl/t-zPKJ1WjbhQ
as i mentioned this is a 1 go geo import of 30 million polys so the zip file is 575 mo can't do much about this i'm sorry.
Hope you'll find something !
Now, i remember having same exact feeling with a geo that was like this one, it was in octane 2 and with c4d plugin, same thing : numerous small unclosed cubes for windows,
but at that time the geo was coming from another soft package so i thought the software was the cause, geo was loading or not sometimes, plugin in c4d crashing while IPR rendering or not sometimes.
Have a good day JuanJgon,