I'm guessing this:
https://kb.juniper.net/InfoCenter/index?page=content&id=KB30135&pmv=print&actp=LIST
Ex4600 isn't explicitly listed but since it's the same chipset it's likely also an issue for it.
https://kb.juniper.net/InfoCenter/index?page=content&id=KB30135&pmv=print&actp=LIST
Ex4600 isn't explicitly listed but since it's the same chipset it's likely also an issue for it.