Since moving to Platinum I'm having big problems with the 64Bit engine.  I have never turned on the 64 bit double precision floating engine back on after having to turn it off after the issues that were introduced with X3 but I do normally turn on the 64bit engine tick box when I am doing a bounce out.
 
When I do this I get a few seconds of audio a long bleep and then the rest of the WAV is rendered as silence.  Been a problem ever since upgrading to platinum. 
 
Not sure if my signature is up to date but my specs are:
Intel Quad Core i7-4790K CPU @4.00 GHz
32GB RAM
Samsung SSD 840 EVO 250GB - OS Drive
2 x WD Black Drives for Audio and Samples
Presonus 1818VSL
 
 

I haven't tried it with the latest platinum braintree update.

I have also experienced an issue with 64 bit precision engine when jumping to different positions in a project during playback (clicks/pops/dropouts) in platinum (not in X3E) meaning I have to turn it off.

My advise is to update your audio interface firmware and drivers first and make sure you are on Braintree.

Oh and another thing, cakewalk advised me to update my display drivers (sadly did not work in my case, probably won't work in yours but a good idea to rule it out as well).

Thanks all Drivers up to date but didn't work

Just shut it off and leave it. There are a few power users that keep it turned off and they don't seem to be missing anything. My needs are very simple but I don't use that option because at one time it was suspected of causing instability for some systems. Haven't bothered with it since X1.

Not much help perhaps, but I have the 64 bit engine active in Braintree and no problems with it so far...

It seems to be very system dependant whether it causes problems or not. Or at least, some people have problems with it while others don't. That's the trouble with PCs - there can be thousands of variables in haedware but it's still "a PC". Even two built from what are nominally the same component parts can't be certain of having e.g. exactly the same capacitors in the video card or absolutely identical motherboard circuits.

I was just playing with this last night.  The 64-bit when exporting is 3 times as slower than the 32-bit (leaving 64-bit unchecked) with no perceptible audio difference.
 
rafone

Unfortunately the new update makes 64 bit precision worse if anything at my end.

Anybody have issues with precision engine and Saffire Pro 40 like I do?
Or Presonus 1818VSL like the OP ?
 

It definitely makes a difference in headroom to my ears and it seems daft to have to turn it off as it was one of Sonars major selling points that it was first to be wall to wall 64bit.  Surely one of it's key selling points should be rock solid three releases later?

P-Theory
It definitely makes a difference in headroom to my ears and it seems daft to have to turn it off as it was one of Sonars major selling points that it was first to be wall to wall 64bit.  Surely one of it's key selling points should be rock solid three releases later?

32 bit floating point doesn't clip until you're more than +700 dBFS, so your definite difference in headroom is definitely imaginary. It is however technically quite true that 64 bit fp gives you more headroom, as the marketing claims.