You could have reproduced this if you maxed out performance with physics props with animations rather than asked me for my project.

Hi Molly, I'd really like to help solve and test this with you but I can't afford spending that much unpaid time so for now I will settle for the work around which is directly entering 0 or 1 to completely rewind.  

I did imply that Reallusion should stress test this scenario by making  and testing a resource intensive project. My iClone installation is completely fresh (less than a month) with folder and reg clean directed by Rampa and although this issue is a bit of a hiccup, same with smart gallery that has suddenly stopped loading (error -6) I have to turn a blind eye to these and get work done.

Let me know how it goes after stress testing on your side, then we'll know or not whether it might be project specific.  With the particular project I have I'm using  both cloth physics and a chain link with constraints, displacement, smooth mesh by subdivision L1, human shader  with 4k max texture resolution. 

So just for now, I can't go through all the hoops, maybe later when things are better. Thank you.

Hi Molly, yes, the start button is the issue. I can't share my project unfortunately but it happens in any project where operations are resource heavy (physics, many props loaded with animations etc)  I have also recently had iClone uninstalled, reg cleaned and iClone reinstalled. I'm using an i7, 32 GB, RTX 2080Ti and over 30 -50 GB free on my SSD hard drive.

So entering frame 1 and pressing enter is a smooth operation but pressing start usually under 10 times causes a crash.  Also I can manually enter frame 1 but switching the Time unit in project settings to "Time" doesn't allow any numbers to be entered, I don't know if that is normal but it's very odd that we can't access it, I have audio projects in another program that allow me to label on time stamps and keep scenes organized, punching in time units in iClone would be very efficient/normal if it exists.