Corrupted block database detected

[JBF12]

I keep receiving “corrupted block database detected” when trying to open btc core. Click OK to “do you want to rebuild the block database now?” Then another error message appears and says- Error: Error opening block database. Click OK then btc core shuts down. How can I fix this issue? Non technical user. Thanks

[1714550648]

1714550648

[1714550648]

1714550648

[Upgrade00]

The pop up message is likely because you do have a corrupted database. Here's a recent thread I found, and a user with the exact same issue as yours, helped by one of the forum members here;

Your database is likely corrupted. Try wiping out the block index with bitcoin-qt -reindex. This will re-make the database by going all over the blk.dat files, re-validate them and rebuilding the chainstate. It'll take a lot of time.

Have you checked your debug.log for further info?

Read from reply #75 down for a step by step process on how to possibly fix the issue.

[JBF12]

Thank you! I’ll look this over.

[NotATether]

If that doesn't work, you can force a reindex by deleting the contents of the blocks/ and chainstate/ folders inside the data directory (usually ~/.bitcoin or C:\Users\blabla\AppData\Roaming\Bitcoin).

[nc50lc]

If that doesn't work, you can force a reindex by deleting the contents of the blocks/ -snip-

Deleting blocks' contents will cause 'initial block download' since those are the blocks.dat files,
If he'll have to resort to file deletions, he can delete the contents of blocks/index instead (& chainstate) but --reindex or --reindex-chainstate should work.

I keep receiving “corrupted block database detected” when trying to open btc core. Click OK to “do you want to rebuild the block database now?” Then another error message appears and says- Error: Error opening block database.

The error that you're getting can also be caused by corrupted chainstate and --reindex-chainstate is a lot faster than --reindex.
You can try it instead but it's better if you check the errors from "debug.log" first so you'll know which command to use:

If your blockchain is pruned, either of those commands will trigger IBD which require you to redownload all the blocks from start.

[JBF12]

I can’t seem to find the “bitcoin” directory when searching through Program Files (x86). Any suggestions?

[PawGo]

In the properties (or in bitcoind.conf file) you should see the parameter responsible for the data directory.

[nc50lc]

I can?t seem to find the ?bitcoin? directory when searching through Program Files (x86). Any suggestions?

Are you looking for bitcoin-qt.exe to be able to use --reindex or the data directory to delete the suggested files?

If the former: it should be in "Program Files" not the Program Files for 32-bit programs.
But that's only if you didn't changed the default directory when you installed Bitcoin Core.
Another way to find the installation directory (if you forgot where) is to use the shortcut(s).
If you have a shortcut on your desktop/start menu (pinned app), right-click on it and select "Open file location" and it will take you where bitcoin-qt.exe is.

If the latter: It should be in your %appdata% folder if you didn't set a custom data directory.
To access it, launch "run" (WinKey+R), type %appdata% and enter, there should be a bitcoin folder there.

[HCP]

I can’t seem to find the “bitcoin” directory when searching through Program Files (x86). Any suggestions?

Are you looking for the bitcoin directory where the actual Bitcoin Core executable (.exe) file is... or the bitcoin directory where the block data, debug.log and wallet data are stored?

[JBF12]

I honestly have no idea. I know where to find the bitcoin-qt.exe file if that’s what i need.

[DaveF]

I honestly have no idea. I know where to find the bitcoin-qt.exe file if that’s what i need.

No, the exe file is in a separate location.
If you did not change the default location, as stated above the data files are in C:\users\your_user_name\AppData\Roaming\Bitcoin\

How large is your harddrive?
What was the last thing that happened before started getting the error?

Corruption is usually (not always) caused by not shutting down the program properly / waiting for it to exit before shutting down the PC
OR since the IBD (initial block download) does put a bit more stress on a drive then normal PC use it may be the drive has some issues.

-Dave

[JBF12]

I think it’s 1tb.
Last thing before it started happening was just simply running it. I let it shut down before powering off each time.
I bought a cheap pc to run it on, not using it for any daily activity.

[JBF12]

Okay, I used the winkey+r and found the bitcoin folder. I also see other folders and files mentioned previously.

[nc50lc]

I honestly have no idea. I know where to find the bitcoin-qt.exe file if that’s what i need.

Good, then follow these instructions to run bitcoin-qt.exe with --reindex parameter: http://bitcointalk.org/index.php?topic=5405156.msg60513193#msg60513193
You'll only need the bitcoin data directory if you want to delete the suggested files, otherwise, reindex will already do that on its process.

Take note that if your Core has "pruning" settings enabled, adding that parameter or deleting chainstate/index folder will trigger a full re-sync instead.

[JBF12]

Ok I’m going to give this a shot. First ever attempt using command line I’m sure I’ll have additional questions. All the help is much appreciated!

[NotATether]

Ok Im going to give this a shot. First ever attempt using command line Im sure Ill have additional questions. All the help is much appreciated!

Once you open Bitcoin-Qt with --reindex parameter from the command line, you can safely close the CMD window as it is not needed anymore (it won't close the Bitcoin-Qt program).

[JBF12]

Looks like it might’ve worked. Is it downloading the entire blockchain again? Seems to be going quicker than the first time.

[nc50lc]

Looks like it might’ve worked. Is it downloading the entire blockchain again? Seems to be going quicker than the first time.

Open your settings in: "Settings->Options..." and see if "Prune block storage to" is ticked.

If it has a check, then it's really downloading the whole blockchain again since there's no way to remake the block index from the blocks that was already pruned.
If it's not checked, it's just verifying the already-downloaded blocks and creating a new index as well as fetching the UTXO set for your wallets.