!!!SOLVED!!! (read on)
In my case, .18 created (and left in place) a DUPLICATE "AttachedDevice" node that led vbox to attempt to open, err... mount the same volume TWICE (failing the second time, of course). Here's the relevant portion of the .vbox file:
Code: Select all
<StorageControllers>
<StorageController name="IDE Controller" type="PIIX4" PortCount="2" useHostIOCache="true" Bootable="true">
<AttachedDevice passthrough="false" type="DVD" port="0" device="0">
<Image uuid="{eebf0531-6c89-4839-b27b-8d4410bb8c5b}"/>
</AttachedDevice>
<AttachedDevice passthrough="false" type="DVD" port="1" device="0">
<Image uuid="{eebf0531-6c89-4839-b27b-8d4410bb8c5b}"/>
</AttachedDevice>
</StorageController>
TO FIX THIS ISSUE...
-1) QUIT VirtualBox;
0) BACKUP your .vbox file; (nee, your ENTIRE VM directory)!
NOTE: In my case it was at ~/VirtualBox VMs/<name of vm>.vbox
1) Open the .vbox file associated with the inaccessible VM (in an editor);
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EDITOR INFO (for those in great pain)
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I used TextWrangler (google it). "Word" is NOT an editor!
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2) Scroll to the bottom of the file;
3) Near the bottom you'll see something similar to what appears below:
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<AttachedDevice passthrough="false" type="DVD" port="0" device="0">
<Image uuid="{eebf0531-6c89-4839-b27b-8d4410bb8c5b}"/>
</AttachedDevice>
<AttachedDevice passthrough="false" type="DVD" port="1" device="0">
<Image uuid="{eebf0531-6c89-4839-b27b-8d4410bb8c5b}"/>
</AttachedDevice>
4) Remove the duplicate "AttachedDevice" (XML) node. (that means all text from "<AttachedDevice " through "</AttachedDevice>").
From this:
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<AttachedDevice passthrough="false" type="DVD" port="0" device="0">
<Image uuid="{eebf0531-6c89-4839-b27b-8d4410bb8c5b}"/>
</AttachedDevice>
<AttachedDevice passthrough="false" type="DVD" port="1" device="0">
<Image uuid="{eebf0531-6c89-4839-b27b-8d4410bb8c5b}"/>
</AttachedDevice>
To this:
Code: Select all
<AttachedDevice passthrough="false" type="DVD" port="0" device="0">
<Image uuid="{eebf0531-6c89-4839-b27b-8d4410bb8c5b}"/>
</AttachedDevice>
5) Save;
6) Quit (editor);
7) Start VirtualBox (manager);
BEFORE YOU LAUNCH THE VM!!! Go into Settings and remove the GuestAdditions.iso from the storage UI);
8a) Select VM (one click. one click only!);
8b) Click Settings (button);
8c) Click Storage (button);
8d) Select GuestAdditions.iso from the list of disks;
8e) Click the remove button (a little minus sign);
8f) Click OK;
9) NOW you can start the VM.