Somehow my password got corrupted

[Dwedit]

I have a copy of FluxBB that has been upgraded many many times, and it was originally Punbb.

I'm not sure how this happened, but somehow my password became incorrect. I had to go into the database and manually change the hash. (You take the Password, append the Salt from the config file, compute SHA1, write that hash as lowercase hexadecimal)

[MioVisman]

If you moved from FLUXBB to FLUXBB_BY_VISMAN, then you need to check the settings in the /Include/config.php.
For the last revision, it looks something like this:

<?php

$db_type = ...;
$db_host = ...;
$db_name = ...;
$db_username = ...;
$db_password = ...;
$db_prefix = ...;
$p_connect = false;

$cookie_name = ...;
$cookie_domain = ...;
$cookie_path = ...;
$cookie_secure = ...;
$cookie_seed = ...;
$cookie_samesite = 'Lax'; // Strict, Lax or None

$salt1 = ''; // <-- Here the line is empty (zero length) for the database Punbb/Fluxbb

define('PUN', 1);

define('PUN_DEBUG', 1);
define('PUN_SHOW_QUERIES', 1);
define('PUN_MAX_POSTSIZE', 65535);
//define('FORUM_EOL', "\r\n"); // possible values can be PHP_EOL, "\r\n", "\n" or "\r"
//define('FORUM_UA_OFF', 1);
define('FORUM_AJAX_JQUERY', 'js/jquery-1.12.4.min.js');
//define('FORUM_SQLITE3_BUSY_TIMEOUT', 10000); // for SQLite
//define('FORUM_SQLITE3_WAL_ON', 1); // for SQLite

// Error display mode (this option for debugging, on the working server you can remove these lines)
error_reporting(E_ALL);
ini_set('display_errors', 1);
ini_set('log_errors', 1);