CS5 crashes when launching Nik collection progra

My iMac OS was El Capitan. After purchasing a Panasonic G95 which was quite a new model, my DNG converter was not able to convert the RAW files. I need to do a conversion because my CS5 not able to open RAW unless it is converted to DNG.

So the next best thing for me to do is to upgrade the DNG converter to v11.3.0.197. One thing leads to another. I must first upgrade my OS to High Sierra which I have done.

I was already prepared to subscribe to Cloud CC after upgrading the OS as I forsee CS5 will not useable with High Sierra. But after launching CS5, I was prompted to install a Java Script in which I did. Lo and behold, the CS5 is still useable which I was so familiar without the need to subscribe to CC. However, whenever I launch the plugin Silver Efex  Pro 2 (v 1.2.11), CS5 closes. It also closes when I launch Colour Efex Pro 4.  I hv uninstalled and reinstalled both products but to no avail.

I have written to DXO and their reply was they are not responsible for the gitch as both products were bought even before Google bought over.

Any help?