i meant if other versions of your own vsts did work with it, there must be something in your program what cubase doesn't like, i had this with repeat x, one of my plugins, i had to change a huge part of the plugin to make it work, at the end i saw that it was just really bad programmed from my side and with the new much smarter solution it worked well.....
i really recommend to test your plugins in the daw during the whole growing process and save every working version, this is really important if you break something working or when you include something which makes it crash, other wise it is nearly impossible to find the part which breaks it....
so you can start with a simple volume vst and try if it works with your daws and then start to enlarge them till it makes troubles, only then somebody from the forum or the devs can help.... with "my plugin crashes, its the fault of FS" it is difficult to help you