"iMac.sparsebundle" could not be accessed (error(null))

Question

My time capsule backups of my iMac to the time capsule has not worked since Nov 11.  I think I may have turned it off at that time because the frequent updates were slowing down my iMac.  Since then I've upgraded the RAM.  When I turned on the Time Capsule back-ups, however, I keep getting an error message:
"The backup disk image "/Volumes/My Time Capsule/My iMac.sparsebundle" could not be accessed (error(null)).
I don't have a disk for my current Operating system, which is OS X 10.9.2.  I have downloaded my last several upgrades thru the Apple Store.
I have gone thru some of the simple steps rebooting everything.  I started the Terminal and gave the commands that Linc Davis suggested in Oct 2013, article with same message, but (error(-1)).  I got the lines below:
I really don't know what to do during a safe mode restart. 
Can anybody help me to get my Time machine working again?
Thanks for any help,
docnsg
#1
com.trusteer.driver.gakl_driver_2 (1)
#2
com.trusteer.rooks.rooksd
com.oracle.java.Helper-Tool
com.adobe.fpsaud
#3
jp.co.canon.cijscannerregister.54944
com.hp.devicemonitor
com.trusteer.rapport.rapportd
com.targus.agent
com.oracle.java.Java-Updater
com.hp.messagecenter.launcher
com.hp.help.tocgenerator
com.conduit.loader.Agent
com.adobe.ARM.202f4087f2bbde52e3ac2df389f53a4f123223c9cc56a8fd83a6f7ae
#4
/Library/Components:
/Library/Extensions:
ATTOCelerityFC8.kext
ATTOExpressSASHBA2.kext
ATTOExpressSASRAID2.kext
ArcMSR.kext
CalDigitHDProDrv.kext
HighPointIOP.kext
HighPointRR.kext
PromiseSTEX.kext
SoftRAID.kext
/Library/Frameworks:
AEProfiling.framework
AERegistration.framework
Adobe AIR.framework
AudioMixEngine.framework
HPSmartPrint.framework
NyxAudioAnalysis.framework
PluginManager.framework
iTunesLibrary.framework
/Library/Input Methods:
/Library/InputManagers:
CTLoader
/Library/Internet Plug-Ins:
AdobePDFViewer.plugin
AdobePDFViewerNPAPI.plugin
CitrixICAClientPlugIn.plugin
Default Browser.plugin
Flash Player.plugin
JavaAppletPlugin.plugin
Quartz Composer.webplugin
QuickTime Plugin.plugin
flashplayer.xpt
iPhotoPhotocast.plugin
nsIQTScriptablePlugin.xpt
/Library/Internet Plug-Ins (Disabled):
Flash Player.plugin
/Library/Keyboard Layouts:
/Library/LaunchAgents:
.DS_Store
com.conduit.loader.agent.plist
com.hp.help.tocgenerator.plist
com.hp.messagecenter.launcher.plist
com.oracle.java.Java-Updater.plist
com.targus.agent.plist
com.trusteer.rapport.rapportd.plist
/Library/LaunchDaemons:
com.adobe.fpsaud.plist
com.oracle.java.Helper-Tool.plist
com.trusteer.rooks.rooksd.plist
/Library/PreferencePanes:
Flash Player.prefPane
JavaControlPanel.prefPane
RapportPreferences.prefPane
Targus.prefPane
/Library/PrivilegedHelperTools:
/Library/QuickLook:
GBQLGenerator.qlgenerator
iBooksAuthor.qlgenerator
iWork.qlgenerator
/Library/QuickTime:
AppleIntermediateCodec.component
AppleMPEG2Codec.component
/Library/ScriptingAdditions:
ct_scripting.osax
/Library/Spotlight:
GBSpotlightImporter.mdimporter
Microsoft Office.mdimporter
iBooksAuthor.mdimporter
iWork.mdimporter
/Library/StartupItems:
Parallels
ParallelsTransporter
/etc/mach_init.d:
/etc/mach_init_per_login_session.d:
/etc/mach_init_per_user.d:
Library/Address Book Plug-Ins:
Library/Fonts:
Library/Input Methods:
.localized
Library/Internet Plug-Ins:
fbplugin_1_0_3.plugin
Library/Keyboard Layouts:
Library/LaunchAgents:
com.adobe.ARM.202f4087f2bbde52e3ac2df389f53a4f123223c9cc56a8fd83a6f7ae.plist
Library/PreferencePanes:
Library/Services:
.localized
#5
GrowlMenu, GrowlHelperApp, iTunesHelper, Stickies, Alfred

Answer 1

First, if this is your only backup, you must make another full backup to a locally-attached external hard drive. One backup is never enough to be safe, and backing up over a network is less reliable than backing up locally. Then try each of the following steps that you haven't already taken.
1. Restart the backup device. You can do that by disconnecting and reconnecting the power cord.
2. Hold down the option key and select Verify Backups from the TM menu in the menu bar (not the Dock icon.) This operation may take several hours. If the menu-bar icon (a clock that runs backwards) isn't showing, check Show Time Machine in menu bar in the preferences.
3. Erase the backup device. With a Time Capsule, you do that from within the AirPort Utility application; see its built-in help for details. All backups will be lost, so don't do this until you've backed up to another device. After erasing, select the TC again as a backup destination in the TM preference pane. The first backup should be made over a wired connection, if possible.