Help! "Couldn't start Dropbox" error (Mac & Big Sur)

I gave up and reinstalled my Dropbox files from the cloud. So that was

mv Dropbox XDropbox

and then reinstall Dropbox and let it move all my files bact to $home/Dropbox.

This was several GB of stuff and it took over a day. It seems to be cleaning up now and the files are back where they were supposed to be.

Yes, Thank you!

bn.BUILD_KEY: Dropbox
bn.VERSION: 125.4.3474
bn.constants.WINDOWS_SHELL_EXT_VERSION: 48
bn.is_frozen: True
machine_id: 2c3c648f-c737-5a9a-abee-fc58ad5e4850
pid: 765
ppid: 1
uid: 501
user_info: pwd.struct_passwd(pw_name='victoriabaum', pw_passwd='********', pw_uid=501, pw_gid=20, pw_gecos='Victoria Baum', pw_dir='/Users/victoriabaum', pw_shell='/bin/bash')
effective_user_info: pwd.struct_passwd(pw_name='victoriabaum', pw_passwd='********', pw_uid=501, pw_gid=20, pw_gecos='Victoria Baum', pw_dir='/Users/victoriabaum', pw_shell='/bin/bash')
euid: 501
gid: 20
egid: 20
group_info: grp.struct_group(gr_name='staff', gr_passwd='*', gr_gid=20, gr_mem=['root'])
effective_group_info: grp.struct_group(gr_name='staff', gr_passwd='*', gr_gid=20, gr_mem=['root'])
DYLD_LIBRARY_PATH: None
cwd: '/'
real_path='/'
mode=0o40755 uid=0 gid=0
parent mode=0o40755 uid=0 gid=0
HOME: '/Users/victoriabaum'
appdata: '/Users/victoriabaum/.dropbox/instance1'
real_path='/Users/victoriabaum/.dropbox/instance1'
mode=0o40700 uid=501 gid=20
parent mode=0o40700 uid=501 gid=20
dropbox_path: '/Users/victoriabaum/Dropbox'
real_path='/Users/victoriabaum/Dropbox'
mode=0o40700 uid=501 gid=20
parent mode=0o40755 uid=501 gid=20
sys_executable: '/Applications/Dropbox.app/Contents/MacOS/Dropbox'
real_path='/Applications/Dropbox.app/Contents/MacOS/Dropbox'
mode=0o100755 uid=501 gid=20
parent mode=0o40755 uid=501 gid=20
trace.__file__: '/Applications/Dropbox.app/Contents/Resources/python-packages.zip/dropbox/client/ui/common/boot_error.pyc'
real_path='/Applications/Dropbox.app/Contents/Resources/python-packages.zip/dropbox/client/ui/common/boot_error.pyc'
not found
parent not found
tempdir: '/var/folders/hf/cvc87mbj0pb6sz93j3x81ksc0000gn/T'
real_path='/private/var/folders/hf/cvc87mbj0pb6sz93j3x81ksc0000gn/T'
mode=0o40700 uid=501 gid=20
parent mode=0o40755 uid=501 gid=20
Traceback (most recent call last):
File "dropbox/client/main.pyc", line 819, in wrapper
File "dropbox/client/main.pyc", line 6472, in finish_dropbox_boot
File "dropbox/client/message_queue.pyc", line 307, in _wrapped
File "dropbox/client/main.pyc", line 6005, in _init_components_for_account
File "dropbox/client/main.pyc", line 5932, in create_sync_engine
File "dropbox/sync_engine_boundary/factory.pyc", line 225, in make_sync_engine
File "dropbox/sync_engine/nucleus/classic_client/sync_engine.pyc", line 275, in __init__
File "dropbox/sync_engine/nucleus/classic_client/modern_client/modern_client.pyc", line 219, in __init__
File "dropbox/sync_engine/nucleus/classic_client/modern_client/base.pyc", line 149, in __init__
File "dropbox/sync_engine/nucleus/classic_client/thin_adapter/in_proc.pyc", line 223, in __init__
File "dropbox/sync_engine/nucleus/classic_client/thin_adapter/in_proc.pyc", line 597, in _init_new_engine_locked
File "dropbox/sync_engine/nucleus/thin_client/client.pyc", line 182, in __init__
File "extensions/nucleus/nucleus_python.pyx", line 76, in nucleus_python.NucleusSyncEngine.__cinit__
nucleus_python.SyncEngineError: "Initializing engine |>> Initializing filesystem |>> Attempting to register icons |>> Opening dst |>> open syscall |>> Permission denied"

Same problem here. New iMac, BigSur 11.6, transfer all old data through TimeMachine backup and now Dropbox can't start with this error .

No way. I tried everything I found here and other sites

This is the log:

Had same problem after installing Big Sur, if you look on hard drive there is a shared folder with a load of junk folders created by the install, deleting these and restarting dropbox forces it to unlink, you then login to dropbox again and synchronise from the cloud again.

Hi,

To be super clear, when you say "delete DB folders from local storage, and empty bin" do you mean deleting all of your existing dropbox folders on your computer? While I can't open the app, the folders are still available to me there. Thanks!

Happened after Montery upgrade.  Tried this solution, didn't work.