cubase 9 and 9.5 constantly crashing

does any expert have any ideas what I can try next?

I use a imac i5 I upgraded to cubase version 9 then 9.5 but have had constant crashing issues in both versions
firstly it will crash at start up the first time it’s run for the first time,this happens everytime, second time I retry it works, removed all the vst plugins as suggestedt, still the same, disabled preferences still the same.

secondly it will crash randomly while running I’ve set it to autosave every 5 mins which has helped save my work multiple times but still a pain having to wait for it to save so often, it spoils workflow.

it will hang sometimes when rendering audio and most times while seaching mediabay, i noticed even if I change the mediabay settings it doesn’t save, after scanning folders and they have turned orange if i close it and reopen they have gone red again.

I love cubase i’ve used it since the early 90’s but i’m really struggling with it at the moment, I sent a few crash log reports to steinberg 2 weeks ago now response yet. i don;t seem to be alone with these issues, i’m pretty sure from memory cubase 8 was stable

does anyone have any new ideas what i can try please?