MultiBit Won't Open? Fixes

Before you continue

Do not delete or overwrite original wallet data.
Make at least two copies before attempting any repair.
Preserve the original folder structure where possible.
Do not install random tools found through search advertisements.
Do not enter wallet words into a website.
Do not send private keys, wallet files or passwords through ordinary email.
Verify software signatures and hashes where possible.
Verify at least one historical Bitcoin address before assuming a wallet is correct.
After recovery, transfer funds to a newly generated, maintained wallet.

The short answer

A launch failure alone does not mean the bitcoin has been lost. Most won't-open problems are Java or sync-file issues. Install Java 8 (ideally in an isolated offline VM), rename the spvchain/checkpoints files (never the wallet file) — or skip the app and restore your seed / extract Classic keys directly. Verify your known receiving addresses on an independent block explorer before drawing conclusions.

Why MultiBit stops opening

MultiBit was discontinued in 2017 and depends on an old Java runtime. On modern Windows and macOS it commonly fails to start because the system Java is too new, missing, or 32-bit while the app expects 64-bit. The other classic culprits are a corrupted sync file (stuck at "syncing"), leftover lock files from a crash, or a corrupted .wallet file.

Step 1 — back up the wallet file first

Before changing anything, copy your wallet data somewhere safe: .wallet/.key files for Classic, and mbhd.wallet.aes plus your seed phrase for HD. Your private keys live in these files — the app is disposable, the keys are not.

Step 2 — fix Java errors

MultiBit Classic was built against Java 8-era runtimes. If it crashes instantly or shows a Java error, install a 64-bit Java 8 runtime and make sure it's the active JVM before launching MultiBit — ideally inside an isolated offline virtual machine configured for the matching historical OS and runtime, rather than downgrading your normal system-wide Java. On macOS, Gatekeeper may also block the unsigned app — right-click → Open once to allow it.

Step 3 — clear the stuck sync

If MultiBit opens but hangs at "syncing" or shows an empty balance, the cached blockchain headers (spvchain, checkpoints) are likely stale or corrupted. Close the app, rename only those files (add .disabled), and relaunch so it rebuilds them. Don't permanently delete anything until recovery is complete. Never delete the .wallet file while doing this.

Step 4 — remove leftover lock files

A crashed session can leave a .lock file that stops a new instance from opening. Close everything, confirm no MultiBit process is still running, then rename any .lock file in the MultiBit data folder and try again. Deleting a lock while the wallet is still running can cause concurrent access or corruption.

Step 5 — recover without the app at all

You don't actually need MultiBit to run to reach your bitcoin:

HD: restore your 12-, 18- or 24-word seed in Electrum (BIP39, path m/0') — see the seed restore guide.
Classic: import unencrypted .key exports, or read the .wallet file with a carefully vetted open-source tool (verify its source and hashes, run it offline) to extract the keys — see exporting private keys.

Restore an HD seed

Keep your wallet file private

Anyone with your seed phrase, plain private keys or a successfully decrypted wallet backup can control the associated funds. Encrypted wallet files are also highly sensitive and must be protected, even when the password is not currently known.

MultiBit won't open FAQ

Why won't MultiBit start on my new computer?

Usually Java: MultiBit needs a 64-bit Java 8 runtime, which is often missing on modern systems or replaced by a newer version. Install Java 8 and relaunch — ideally inside an isolated offline virtual machine so you don't change your system-wide Java setup.

Does deleting the spvchain file help?

Yes, when MultiBit is stuck syncing. With the app fully closed, rename only the spvchain/checkpoints files (add .disabled) so MultiBit rebuilds its blockchain headers — never touch your .wallet file, and don't permanently delete anything until recovery is complete.

Are my bitcoins gone if MultiBit won't open?

Not by itself. The coins are on the blockchain; your access is in the wallet file (.wallet/.key for Classic, mbhd.wallet.aes + seed for HD). A launch failure alone does not prove the funds are lost — verify your known receiving addresses on an independent block explorer before drawing conclusions. Even without the app you can export keys or restore the seed in Electrum.

How do I get to my bitcoin if the app won't start?

Restore an HD seed in Electrum (BIP39, path m/0'), or extract Classic keys from the .wallet/.key files with a carefully vetted open-source tool. No MultiBit installation is required.

Does MultiBit still work in 2026?

The software still installs, but syncing with today's Bitcoin network is unreliable and there are no security updates. Use it only to access existing funds, then move to a modern wallet like Electrum.

MultiBit won't open on Windows 10 or Windows 11 — what should I do?

MultiBit is old Java software, and modern Windows often blocks it. Install a 64-bit Java 8 runtime (ideally in an isolated offline VM), run the installer from preserved original release records (Windows may warn about the unsigned app), and if it still won't start, recover the keys without the app: restore your HD seed in Electrum or extract Classic keys from the .wallet file with a carefully vetted open-source tool.

MultiBit shows a blank screen or freezes on startup — what should I do?

A blank or frozen window on launch is usually a Java or sync problem, which by itself does not mean the funds are lost. Close the app, install a 64-bit Java 8 runtime (ideally in an isolated offline VM), rename the cached spvchain/checkpoints files (never the .wallet file) and relaunch. If it still freezes, skip the app entirely and recover the keys from your wallet files directly.

MultiBit crashed or stopped working — are my coins lost?

A crash does not by itself move or erase bitcoin: the coins are on the blockchain and your access is in the wallet file (.wallet/.key for Classic, mbhd.wallet.aes plus seed for HD). Verify your known receiving addresses on an independent block explorer before drawing conclusions. Even if MultiBit never opens again, you can export the keys or restore the seed in Electrum.

MultiBit says my wallet file is corrupted or can't be read — what now?

A 'wallet could not be loaded', 'cannot read wallet' or 'decryption failed' message does not mean your bitcoin is gone. First make a backup copy of the file before touching anything. Then try opening it in the correct MultiBit version, or restore an HD seed in Electrum — for Classic, extract the keys from the .wallet/.key files with a carefully vetted open-source tool (verify its source and hashes, run it offline), which often works even on a partially damaged file.

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