During the last few weeks a common, reoccurring, question seems to be how to get one's blockchain "unstuck". This guide will, hopefully, provide some assistance in doing so.
Note that, if you are stuck on block
1288639 (or block
1400001) or a few blocks later, you are using a wrong, outdated, version and you should upgrade to the latest version, which can be found here. In addition, this won't require a resync from scratch, as the "new"
monerod will automatically use the blockchain that was used with the previous version and pick up syncing where it left off.
The first step in getting your blockchain unstuck is making sure that no Monero related process is running anymore. Thus, close the GUI by clicking on the
x and make sure to stop the daemon as well. If you're using the CLI, type
exit into both
monerod. Thereafter, use your task manager to check whether all Monero related processes are closed. Alternatively, you could simply reboot.
Now that no Monero related processes are running anymore, delete
p2pstate.bin. On Windows it can be found in the following directory:
Note that, by default, the ProgramData directory is hidden. Therefore, use the explorer to manually navigate to aforementioned directory.
On Linux and Mac OS X:
This directory is hidden by default too. On Linux you can use
CTRL + H to unhide directories (note that this might not work on all Linux distributions), whereas on Mac OS X you can use
cmd-shift-dot unhide directories.
After you've deleted
p2pstate.bin you can restart
monerod / the GUI. If this didn't resolve your issue, please read further and make sure
monerod / the GUI is closed again.
We're going to add the following flag:
This will change the batch of fetched blocks from 20 to 10.
You can add the flag as follows:
If you are using the GUI, simply add
--block-sync-size 10 as daemon startup flag. You can do this on the
Settings page of the GUI. Note that you'll have to restart the GUI + daemon for the flag to take effect. Thus, add the flag, exit the GUI and stop the daemon as well, and lastly restart the GUI + daemon.
If you are using the CLI, please see below.
On Windows make sure to launch it from the command line. Go to the folder monerod is located and make sure your cursor isn't located on any of the files. Subsequently do SHIFT + right click and it will give you an option to "Open command window here". Lastly, type the following command:
monerod --block-sync-size 10
On Linux and Mac OS X you should use the terminal to launch
monerod. Note that this has to be done from the directory monerod is located in. The command is as follows:
./monerod --block-sync-size 10
If your blockchain is still stuck after adding this flag, please browse again to
C:\ProgramData\bitmonero (Windows) or
$HOME/.bitmonero (Linux and Mac OS X), open
bitmonero.log and check it for any errors. If you see any of these errors (or similar to them), your blockchain is most likely corrupted and you need to resync from scratch.
Error opening database: Failed to query m_blocks: MDB_BAD_TXN: Transaction must abort, has a child, or is invalid
Failed to parse and validate tx from blob (per MoneroMooo: This can be a corrupt blockchain, if this comes from a block inside the db. However, it's much more likely to be an old version not knowing about a new fork)
This is done by deleting
C:\ProgramData\bitmonero\lmdb (Windows) or
$HOME/.bitmonero/lmdb (Linux and Mac OS X), which will trigger the resync.