I've never seen this error before.  

 
And this was working Thursday night.  No changes since then.  This PC has been off since then!
 
I am rolling back to see if it goes away.  You bit jockeys... what the heck is this message?  Why would this suddenly come up?

The file has become corrupted.  How exactly?  No easy way you can't tell.  Could be a hard drive failure.  Could be some sort of user operation caused the file to become corrupted (file copy/file overwrite/etc).  Could be some sort of utility/antivirus messing with things.  Could be some sort of virus. 
 
Most likely though is hardware failure of some sort.  The file on the disc is now corrupted and the only way to fix that is to restore it from a backup or to reinstall.  But if it was a hardware failure, you may want to look into full system backups and plan for the worst. 
 
 

Space Cowboy,
Exactly the same thing here. Thankfully, it was just an install (latest update with no previous installs) on my (home, cheap general use) windows 10 laptop which I’d tried just for the sake of it to see if it would run. (Main desktop runs fine)
Sonar Platinum installed quite the thing on the laptop and ran a couple of times, but then displayed the same message as yours. A reinstall didn’t fix it.
Just tried again before posting this and same message as yours appeared again.
Not crucial to me as it wasn’t my main desktop, but ….
 

If the file isn't actually corrupted (bad image) it is possible that some of the DLLs/runtime it needs aren't installed/working.  Windows 10 has messed a lot of things up recently.  The 64-bit version of CJLibrary.dll I have is 665,088 bytes and has a MD5 checksum of f2baaaecd11a4c09ed7d2a8f267edb50
 
It needs/uses the following DLL's under Windows 7

    SHLWAPI.dll
    mfc140u.dll
    KERNEL32.dll
    USER32.dll
    GDI32.dll
    ADVAPI32.dll
    SHELL32.dll
    COMCTL32.dll
    OLEAUT32.dll
    VCRUNTIME140.dll
    api-ms-win-crt-time-l1-1-0.dll
    api-ms-win-crt-string-l1-1-0.dll
    api-ms-win-crt-stdio-l1-1-0.dll
    api-ms-win-crt-heap-l1-1-0.dll
    api-ms-win-crt-convert-l1-1-0.dll
    api-ms-win-crt-runtime-l1-1-0.dll
    api-ms-win-crt-filesystem-l1-1-0.dll
    api-ms-win-crt-utility-l1-1-0.dll
 

I know this explanation might sound far fetched but hear me out..
It could also be your antivirus messing with it because of a reputation scan.
It could have been flagged by your AV and then repopulated once you opened sonar again.
thus repopulating wasn't the same as the original and not is being tagged as a corrupt file.
 
I think reinstalling will fix the issue but you might want to do a complete reinstall (including deleting Registry keys)
http://forum.cakewalk.com/FindPost/3650566

That message indicates that the file (or one of its dependencies as listed by Matt above) is corrupt.
 
There is a tool built in to Windows that supposedly (I've never actually seen it do anything) detects and fixes corrupt system files. Open a command prompt as Administrator and type in "sfc /scannow". Be patient, it takes awhile.

I swear I've seen other threads about this exact same message. It's a w10 thing I'm pretty sure,, not Sonar. 

Cactus Music
I swear I've seen other threads about this exact same message. It's a w10 thing I'm pretty sure,, not Sonar.

Was Win10 available in 2013?
http://forum.cakewalk.com/FindPost/1331608
 
EDIT: sorry, pressed send button too early.
 
What I mean, Googling  shows Sonar crashes quite a lot in it, so may be AV guess is right, AV (or other windows component) detects that "something is wrong" with it (but not on the virus level, so no "alarms") and then block it. Check Windows logs, may be they show some "errors" or "warnings" which can clarify what is going on. 

azslow3

Cactus Music
I swear I've seen other threads about this exact same message. It's a w10 thing I'm pretty sure,, not Sonar.

Was Win10 available in 2013?
http://forum.cakewalk.com/FindPost/1331608

I agree with you, here's a post going back to 2008 using Sonar 7.
http://forum.cakewalk.com/quoterror-in-Sonar-startup-in-cjlibrarydllquot-m1331608.aspx

OP ever figure out what was going on ?
another user with similar situation here:
http://forum.cakewalk.com/SONAR-PROGRAMS-WONT-OPEN-m3661474.aspx#3661585
trying to narrow this down. Curious as I asked in my first comment, what Anti virus are you running ?