I'm getting an error when the Dropbox app starts up on Windows 11

Device
(Lenovo laptop)
Operating System/Browser (if using the web)
(Windows 11.)
Dropbox App Version (if using the app)
(latest)

Question or Issue
After booting the PC the dropbox App refuses to start and displays a window with the message "Couldn't start dropbox". The dropbox icon in the taskbar disapears and my files in the dropbox folder are inaccessible by Word, Excel etc.  I did the "Advanced reinstall of Dropbox" as can be found in the fora but no results. I am using Dropbox for many years without any problems.

Below the error report generated by Dropbox. The very last record shows FileNotFoundError but which file is not mentioned. I am really stocked but need a working Dropbox system. Hope I can find some help here.

Date: 3-12-2026

After action: advanced reinstall

Error report: 

bn.BUILD_KEY: Dropbox

bn.VERSION: 237.4.5655

bn.constants.WINDOWS_SHELL_EXT_VERSION: 88

bn.is_frozen: True

machine_id: (content removed by me)

pid: 8816

cwd: 'C:\\Program Files (x86)\\Dropbox\\Update\\1.3.1053.1'

     real_path='C:\\Program Files (x86)\\Dropbox\\Update\\1.3.1053.1'

             mode=0o40777   uid=0    gid=0

     parent          mode=0o40777   uid=0    gid=0

HOME: None

appdata: 'C:\\Users\\admin\\AppData\\Local\\Dropbox\\instance1'

         real_path='C:\\Users\\admin\\AppData\\Local\\Dropbox\\instance1'

                         mode=0o40777   uid=0    gid=0

         parent       mode=0o40777   uid=0    gid=0

dropbox_path: None

                         not found

              parent  not found

sys_executable: 'C:\\Program Files (x86)\\Dropbox\\Client\\Dropbox.exe'

                real_path='C:\\Program Files (x86)\\Dropbox\\Client\\Dropbox.exe'

                         mode=0o100777 uid=0    gid=0

                parent            mode=0o40777   uid=0    gid=0

trace.__file__: 'C:\\Program Files (x86)\\Dropbox\\Client\\237.4.5655\\python-packages.zip\\dropbox\\client\\ui\\common\\boot_error.pyc'

                real_path='C:\\Program Files (x86)\\Dropbox\\Client\\237.4.5655\\python-packages.zip\\dropbox\\client\\ui\\common\\boot_error.pyc'

                         not found

                parent            not found

TMP: C:\Users\admin\AppData\Local\Temp

TEMP: C:\Users\admin\AppData\Local\Temp

tempdir: 'C:\\Users\\admin\\AppData\\Local\\Temp'

         real_path='C:\\Users\\admin\\AppData\\Local\\Temp'

                         mode=0o40777   uid=0    gid=0

         parent       mode=0o40777   uid=0    gid=0

Traceback (most recent call last):

  File "desktop/dropbox/client/main.py", line 6857, in _setup_root_for_account

  File "desktop/dropbox/sync_root/helpers.py", line 199, in create_root_for_account

  File "desktop/dropbox/foundation/futures/basic.py", line 1044, in result

  File "desktop/dropbox/sync_root/manager.py", line 382, in create_root

  File "desktop/dropbox/sync_root/handlers/windows/cloud_files.py", line 299, in register

  File "desktop/dropbox/sync_root/handlers/windows/cloud_files.py", line 601, in _register

FileNotFoundError: [WinError -2147024894] The system cannot find the file specified