It happens whenever I export in real-time using sounds from the S90 XS. The only solution I found online was routing the output to a Group buss. Will it be fixed in the upcoming update? Does it happen in 6?
Thanks
So… I have a serious and (what I’ve recently discovered to be a) well known bug… the 5.5.3 Pre-Announcement mentions nothing of it, all of the search hits about the bug online lead nowhere, and no one here has anything to say about. It simply remains a bug. That is awesomely disappointing.
What if you move the whole song foward by a couple of bars in the timeline and Export?
Thanks for the reply. 
I will be in my studio in a few and will definitely give that a try.
BTW, maybe I missed it, but has Steinberg made any statement about this. Can it be recreated or does it not exist with most users? Workarounds are the nature of this business so I tend not to mind in most cases. However, a fix is always preferred. I will ask the question in my original post in the 6 forum. I’ve been a customer since version 1, but definitely will not upgrade if others are experiencing this super annoyance in 6 as well.
This issue is plug-in and/or soundcard dependant. Some plugs cause it, some don’t. I’ve read that in C6, they’ve left a small space before the first bar to give everything a chance to start at the same time. Not saying it would fix your issue but that’s the reason. You might try increasing your latency/buffer when exporting if that first suggestion doesn’t work. It would help narrow the problem.
Thanks for the suggestions. When I first experienced the problem my first thought was to increase the buffer… no luck. I moved the song forward a few bars, but to no avail.
I did however find the problem for me. First, it is not the S90 XS; there is another session that I recently exported real-time using the S90… it has my same go to plugins except Stylus RMX and Massive (that are used in the session that is getting the error).
So with the option to “Unload Instrument when frozen” I froze Massive… still got the Export error.
Unfroze Massive and did the same thing for the 4 instantiations of Stylus RMX… Froze Stylus RMX Main Kit then exported… still got the error. Also froze Stylus RMX Percussion, then exported… NO ERROR!!!
Although my system is powerful enough to run probably 20 loaded instantiations of Stylus RMX, Cubase 5.5.2 will only Export two in this session. The bug seems to be both plugin and session specific and I can imagine it shows its ugly head base on a ton of unknown variables. I’m not gonna stop using Cubase over it, but it really is a nuisance.
TRY CHANGING EXPORT LOCATION TO OTHER PARTITION OF DRIVE
I don’t have much knowledge but for me the solution was pretty simple… I use C9 on i3 (5th gen) with 12 gb ram.
I was just exporting the project in real-time mode but was saving it in the same partition in which i had my project (i.e. C/desktop). I tried to change the export location (i.e. D/) to other partition and it worked for me.
Pretty Simple 