Could someone remind me how I can start Sonar Plat in safe mode so I can see if I have a problem with a plugin. Thanks in advance.
Sonar is loading but once I try to open a project all I get is the spinning blue ball.

open the project while holding the shift key

Thanks grim. The projects loads fine but when I try to open the browser it hangs with the blue ball. I tried all my other views ie. Staff, console, piano roll etc.  They all open, but only the browser fails to open whether I press B or use the view menu. I have never seen bahaviour like this before.

Try doing a Save As and seeing if creating a new project file corrects it.  If that fixes whatever was wrong with the original project - you can just do a rename of the original project file to something else and then rename the newly created one back to the name of the original.
 
So, if the Fred project may have some project file corruption, open Fred, Save As Fred_new, and if Fred_New behaves properly then close Fred_New, rename Fred as Fred_Old, and then rename Fred_New to its original name of Fred (so it again matches the Project Folder name of Fred.
 
Hope that wasn't too confusing - it's only 6:30 AM here and no coffee yet.
 
Bob Bone
 

Did you have networked/external drives when the project was saved? The browser may be updating to reflect what is currently connected.

I will try that mettulus and leave it running all night to see it that works. I had a portable drive that was acting up with a clicking noise connected to my usb portal. So I unplugged all 5 of my ext drives and probably put them into different slots. But my music data drive is a hard drive in the tower so it has nothing to do with my audio files, loops etc. 
One other odd thing I noticed is that I have no screen sets whatsoever. My laptop is fine and working well with both screensets and the browser. I uninstalled Sonar Plat with the control centre and reinstalled to no avail. I even deleted the cakewalk ini file and rebooted. I will leave it running all night and see if it clears up in the morning wirh a browser refresh and get back to you tomorrow. Its midnight here in Oz 

I tried renaming the project Bob but it made no difference

Tané
The projects loads fine but when I try to open the browser it hangs with the blue ball. I tried all my other views ie. Staff, console, piano roll etc.  They all open, but only the browser fails to open whether I press B or use the view menu. I have never seen bahaviour like this before.

I had this happen in the latest release when I tried to set some of the folder location options under preferences>file>folder locations to a USB3 flash drive. IIRC the plugin layouts folder turned out to be the problematic one. For whatever reason this could not be set to the flash drive or Sonar would freeze either when I tried to open the browser, or tried to load a project which was saved with a screenset in which the browser was already open. Once I moved the folder locations back to the C drive all was well.

when was the last time you updated windows ?
update to the newest version of  Visual C++ Redistributable Package.
Not all updates are critical..but this one is.