Time Machine: sparcebundle could not be accessed (error -1)

Question

Hello!
I’ve using Time Machine with my Time Capsule for some time and out of nowhere it started giving me the following error: The backup disk image “xxx/xxx/xxx.sparcebundle”could not be accessed (error -1).
I’ve been searching weeks for a fix without success, already tried http://pondini.org/TM/Troubleshooting.html - #C17 and it didn’t help.
Also tried on my Time Capsule: unplug, reset, factory reset, erase disk, format disk, change password, and on Time Machine preferences tried to remove disk and add again…. no success, error persists.
I discovered the only way for backup to work is to I login as a test user which I created for this purpose (I’m the administrator).
Any help would be greatly appreciated. Thanks.
Here are the logs:
Backup logged in as Administrator (Backup Failed):
Starting automatic backup
Attempting to mount network destination URL: afp://xxxx%20xxxx;AUTH=SRP@Aar._afpovertcp._tcp.local/Data
Mounted network destination at mount point: /Volumes/Data using URL: afp://xxxx%20xxxx;AUTH=SRP@Aar._afpovertcp._tcp.local/Data
Failed to eject volume /Volumes/Data (FSVolumeRefNum: -166; status: -47; dissenting pid: 0)
Waiting 60 seconds and trying again.
Network destination already mounted at: /Volumes/Data
Failed to eject volume /Volumes/Data (FSVolumeRefNum: -166; status: -47; dissenting pid: 0)
Waiting 60 seconds and trying again.
Network destination already mounted at: /Volumes/Data
Failed to eject volume /Volumes/Data (FSVolumeRefNum: -166; status: -47; dissenting pid: 0)
Giving up after 3 retries.
Backup failed with error: 21
[SnapshotUtilities mountPointForVolumeRef] FSGetVolumeInfo returned: -35
Failed to eject volume (null) (FSVolumeRefNum: 0; status: -35; dissenting pid: -1)
Failed to eject Time Machine disk image: /Volumes/Data/Super’s iMac.sparsebundle
Backup logged in as a test user (Backup completed successfully):
Starting automatic backup
Attempting to mount network destination URL: afp://xxxx%20xxxx;AUTH=SRP@Aar._afpovertcp._tcp.local/Data
Mounted network destination at mount point: /Volumes/Data using URL: afp://xxxx%20xxxx;AUTH=SRP@Aar._afpovertcp._tcp.local/Data
Disk image /Volumes/Data/Super’s iMac.sparsebundle mounted at: /Volumes/Time Machine Backups 2
Backing up to: /Volumes/Time Machine Backups 2/Backups.backupdb
Using file event preflight for Mac HD
Will copy (44.4 MB) from Mac HD
Using file event preflight for Dados
Will copy (Zero KB) from Dados
Found 2280 files (44.4 MB) needing backup
1.5 GB required (including padding), 752.35 GB available
Copied 7285 files (45.2 MB) from volume Mac HD.
Copied 7303 files (45.2 MB) from volume Dados.
Using file event preflight for Mac HD
Will copy (2.6 MB) from Mac HD
Found 58 files (2.6 MB) needing backup
1.59 GB required (including padding), 752.32 GB available
Copied 1122 files (4.4 MB) from volume Mac HD.
Copied 1140 files (4.4 MB) from volume Dados.
Created new backup: 2013-10-02-121637
Starting post-backup thinning
Deleted /Volumes/Time Machine Backups 2/Backups.backupdb/Super’s iMac/2013-10-01-120751 (4.1 MB)
Deleted /Volumes/Time Machine Backups 2/Backups.backupdb/Super’s iMac/2013-10-01-110755 (8.5 MB)
Deleted /Volumes/Time Machine Backups 2/Backups.backupdb/Super’s iMac/2013-10-01-101239 (21.7 MB)
Deleted /Volumes/Time Machine Backups 2/Backups.backupdb/Super’s iMac/2013-10-01-004813 (1.3 MB)
Post-back up thinning complete: 4 expired backups removed
Backup completed successfully.
Ejected Time Machine disk image: /Volumes/Data/Super’s iMac.sparsebundle
Ejected Time Machine network volume.

Answer 1

Please read this whole message before doing anything.
I've tested these instructions only with the Safari web browser. If you use another browser, they may not work as described.
This procedure is a diagnostic test. It won’t solve your problem. Don’t be disappointed when you find that nothing has changed after you complete it.
Third-party system modifications are a common cause of usability problems. By a “system modification,” I mean software that affects the operation of other software — potentially for the worse. The following procedure will help identify which such modifications you've installed. Don’t be alarmed by the complexity of these instructions — they’re easy to carry out and won’t change anything on your Mac. 
These steps are to be taken while booted in “normal” mode, not in safe mode. If you’re now running in safe mode, reboot as usual before continuing. 
Below are instructions to enter some UNIX shell commands. The commands are harmless, but they must be entered exactly as given in order to work. If you have doubts about the safety of the procedure suggested here, search this site for other discussions in which it’s been followed without any report of ill effects. 
Some of the commands will line-wrap or scroll in your browser, but each one is really just a single line, all of which must be selected. You can accomplish this easily by triple-clicking anywhere in the line. The whole line will highlight, and you can then copy it. The headings “Step 1” and so on are not part of the commands. 
Note: If you have more than one user account, Step 2 must be taken as an administrator. Ordinarily that would be the user created automatically when you booted the system for the first time. The other steps should be taken as the user who has the problem, if different. Most personal Macs have only one user, and in that case this paragraph doesn’t apply. 
Launch the Terminal application in any of the following ways: 
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.) 
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens. 
☞ Open LaunchPad. Click Utilities, then Terminal in the icon grid. 
When you launch Terminal, a text window will open with a line already in it, ending either in a dollar sign (“$”) or a percent sign (“%”). If you get the percent sign, enter “sh” and press return. You should then get a new line ending in a dollar sign. 
Step 1 
Triple-click anywhere in the line of text below on this page to select it:
kextstat -kl | awk '!/com\.apple/{printf "%s %s\n", $6, $7}' | open -ef 
Copy the selected text to the Clipboard by pressing the key combination command-C. Then click anywhere in the Terminal window and paste (command-V). A TextEdit window will open with the output of the command. If the command produced no output, the window will be empty. Post the contents of the TextEdit window (not the Terminal window), if any — the text, please, not a screenshot. You can then close the TextEdit window. The title of the window doesn't matter, and you don't need to post that. No typing is involved in this step.
Step 2 
Repeat with this line:
{ sudo launchctl list | sed 1d | awk '!/0x|com\.(apple|openssh|vix\.cron)|org\.(amav|apac|cups|isc|ntp|postf|x)/{print $3}'; echo; sudo defaults read com.apple.loginwindow LoginHook; echo; sudo crontab -l; } 2> /dev/null | open -ef 
This time you'll be prompted for your login password, which you do have to type. Nothing will be displayed when you type it. Type it carefully and then press return. You may get a one-time warning to be careful. Heed that warning, but don't post it. If you see a message that your username "is not in the sudoers file," then you're not logged in as an administrator. 
Note: If you don’t have a login password, you’ll need to set one before taking this step. If that’s not possible, skip to the next step. 
Step 3
{ launchctl list | sed 1d | awk '!/0x|com\.apple|org\.(x|openbsd)/{print $3}'; echo; crontab -l 2> /dev/null; } | open -ef 
Step 4
ls -A /e*/{cr,la,mach}* {,/}Lib*/{Ad,Compon,Ex,Fram,In,Keyb,La,Mail/Bu,P*P,Priv,Qu,Scripti,Servi,Spo,Sta}* L*/Fonts .la* 2> /dev/null | open -ef  
Important: If you formerly synchronized with a MobileMe account, your me.com email address may appear in the output of the above command. If so, anonymize it before posting. 
Step 5
osascript -e 'tell application "System Events" to get name of login items' | open -ef 
Remember, steps 1-5 are all copy-and-paste — no typing, except your password. Also remember to post the output. 
You can then quit Terminal.