Vista VM Fails to Open after Upgrades to OS X 10.9.3 and Parallels 9.0.24229.991745

Help!
After updates, Parallels Desktop will NOT open my Windows Vista 1.pvm virtual machine file!
I tried opening the file from Parallels, and from Finder “open with†Parallels, but nothing happens! (Literally—no new window, nor black nor blue screen, no error message, just nothing … )
Parallels does not offer any error message to explain why!

So, what should I do to recover functionality?
Possible options?
a) do something (???) to make Parallels work? --please, tell me HOW!
b) recover and attempt to open the prior version of the pvm file (saved on Mac OS Time Machine)?
c) revert to prior Parallels Desktop version (saved on Mac OS Time Machine)?
d) something else? --please, tell me HOW!

Facts:
1) Both Parallels and the Vista 1.pvm file worked fine when last opened in April.
2) Backed up both with Time Machine before departure for 3 weeks vacation in Rome.
3) Windows Vista file size 37.54 GB
4) Hardware: MacBook Pro 2.3 GHz Intel Core i7 quadcore, 8 GB 1067 MHz DDR3 memory
5) Hard Drive free space available: 207.55 GB

Upon return from travel today, May 21, 2014, update actions performed:
6) Updated OS X from 10.9.2 to 10.9.3 per Apple Software Update notification
7) Parallels updated to version 9.0.24229.991745 per Parallels Update notification
8) Restarted Mac, twice. Ran Repair Disk Permissions in Disk Utility. Listed repairs did not mention any Parallels application or file.
9) Restarted again. But, no success with Parallels.
10) VM does not open. No indication why. No error message.

Parallels just fails—with no explanation about why.
So, what do I do next to run my Vista VM file?

FYI this is the first major failure of Parallels over 6 years, since I began with version 4! Through all upgrades, the software has always performed reliably—until now! I depend on the app to run some critical financial software not available for Macs. So, please, if there is any solution to this dilemma, advise what to do!
Thanks for any help,
JB

PS—Parallels Knowledge Base articles reviewed, and suggestions followed, with no solution so far:
I) Article ID: 113964 Created On: May 25, 2012 Last Review: May 11, 2014 I am unable to start Windows: troubleshooting Virtual Machine start issues no help
II) Article ID: 113881 Created On: May 13, 2012 Last Review: May 11, 2014 Unable to start the virtual machine as it is stuck in stopping state
Tried the solution offered, with no success:
On the Mac side, open Activity Monitor from /Applications/Utilities/
Find the process: prl_vm_app ('Parallels VM' in Parallels Desktop 8 and 9)
Select this process and quit it by clicking on 'Force Quit' option.
Restart the Virtual Machine and check if you are able to boot it successfully.
III) Article ID: 7076 Created On: Dec 29, 2009 Last Review: May 11, 2014 What processes should I allow in Mac's Firewall for Parallels Desktop?
Already Enabled (green) in Mac Firewall: Parallels Desktop.app, prl_naptd, ntpd (and all other apps listed). Parallels Service.app is not listed. No other firewall or anti-virus software is installed.
IV) Article ID: 8089 Created On: Feb 17, 2010 Last Review: May 11, 2014 Error starting Parallels Desktop: Unable to connect to Parallels Service
No error message whatsoever was generated. This doesn't seem relevant.
V) Article ID: 6338 Created On: May 15, 2009 Last Review: May 11, 2014 How to terminate a frozen virtual machine
This doesn't seem relevant. The VM does not seem “frozenâ€--and does not appear in Activity Monitor.
VI) Sorry, none of these KB articles solved the problem, and searches cannot find any other KB articles that seem possibly relevant.

 

I see no responses to your request for help. Have you gotten any help from somewhere else? I'm holding off on the 10.9.3 upgrade until I see if Parallels 9 is going to work afterwards.