1password installs but won't run

This is all i see in the log

ERROR 2025-08-05T17:30:47.400+00:00 ThreadId(1) [1P:foundation\op-log\src\lib.rs:670] tracing WAS NOT installed
ERROR 2025-08-05T17:30:47.407+00:00 ThreadId(1) [1P:op-settings\src\store\json_store.rs:82] Os { code: 2, kind: NotFound, message: "The system cannot find the file specified." }
INFO  2025-08-05T17:30:47.407+00:00 ThreadId(1) [1P:op-settings\src\store\json_store.rs:118] Settings file "C:\Users\<redacted-username>\AppData\Local\1Password\settings\settings.json" missing, using defaults.
INFO  2025-08-05T17:30:47.413+00:00 ThreadId(1) [1P:foundation\op-startup\src\windows.rs:421] Installer=MSI (x64), ManagedInstall=false, ManagedUpdate=false
ERROR 2025-08-05T17:30:47.413+00:00 ThreadId(1) [1P:foundation\op-startup\src\windows.rs:90] Error HRESULT(0x00000000): The operation completed successfully.
INFO  2025-08-05T17:30:47.420+00:00 ThreadId(1) [client:typescript] 1Password is already running, closing.

Downloaded from https://downloads.1password.com/win/1PasswordSetup-latest.msi

1pw appears in task manager / details then disappears, and the same log entries appear. Rebooted. Removed 1pw, removed remaining directories, reinstalled, same. After this I copied a settings.json from a colleague just to test. Same happens without the complaint on settings.json.

Am I missing something? Prereq? I have latest vcredist 2015-2022 x86 & x64.