Installation failed — recover from a corrupt download

A corrupted install of the Nimbus loader looks like one of: the loader window flashes and disappears, the signature check fails (SignatureMismatch in the boot log), auto-update writes a partial file and exits, or the binary on disk is a different size than what the dashboard claims. All of these are recoverable in under two minutes without resetting your HWID or buying a fresh key.

Step 1: stop the loader cleanly. Open Task Manager (Ctrl+Shift+Esc), sort by name, kill every process called nimbus-loader.exe or loader_helper.exe. If you skip this step the next step will fail because Windows holds a file lock on a running binary.

Step 2: delete the binary and the staging folder. Open File Explorer to wherever you keep the loader (the default is C:\Nimbus\). Delete nimbus-loader.exe, nimbus-loader.exe.pending (auto-update staging file — only present mid-update), and the update\ subfolder if it exists. Do NOT delete %APPDATA%\Nimbus\ — that's where your remembered credentials and config live, and wiping it forces you to sign in again from scratch.

Step 3: re-download from the dashboard. Sign into getnimbus.net/dashboard on a web browser (your phone is fine if your PC's browser is the problem). Click Download Loader. You'll get a fresh nimbus-loader.exe ~3 MB.

Step 4: verify the file integrity. Right-click the downloaded nimbus-loader.exe → *Properties → Digital Signatures*. You should see one signer entry with a valid certificate chain. If the Digital Signatures tab is empty or shows an invalid cert, your download was tampered with mid-flight — most likely by a corporate proxy or an aggressive antivirus. Disable the AV temporarily (or whitelist getnimbus.net) and download again.

Step 5: move it to a stable folder and run. Drop the verified binary into C:\Nimbus\ (or wherever you originally kept it), right-click → Run as administrator. Your saved credentials in %APPDATA%\Nimbus\ are still intact, so the sign-in dialog pre-fills your email; tap Sign in and you're back in.

Common root causes. The corrupt install almost always traces to one of: (a) the loader folder lived on OneDrive / Dropbox / Google Drive and the sync client interrupted the auto-update mid-write, (b) Windows Defender quarantined the binary halfway through a write, (c) you copied the loader manually instead of letting it auto-update and got a partial copy. The fix above resets all three; the long-term fix is to keep the loader off sync folders and to add C:\Nimbus\ to your AV exclusions.