Many stock effect plugins not loading in 7.5 work in wavlab

I have no issue with stock vst’s but many of the stock effect devices just will not load. Have tried reinstalling 7.5 and 7.5.20 but finding some plugins will not load into insert slots. For instance if I select modmachine delay it loads into a slot but selecting monodelay just closes the plugin selection window and leaves an empty slot. Lots more don’t work so I won’t list them but cubase sees the plugins in the manager no problem and funnily enough wavelab 8.5.2 loads all of these plugins no problem so has wavelab (installed after cubase) somehow screwed with my cubase install somehow?

win 7 64 bit
cubase 7.5.20
wavelab 8.5.20