Admin Login Not Working

Has anyone had an issue where you cannot login to you admin panel?  Nothing changed but I'm getting a "Login Failed.  Please Try Again" message.  Not sure why this is happening and how to fix.

So far, the only option seems to be to reinstall Dolphin.  After months of building this site, that seems to be a horrible opption.  Especially when I don't know why this happened.  I was able to login to admin with no problem this morning.  Who's to say this is not going to happen again after reinstallation.

Has anyone else had this problem?  Any way to change Admin login somewhere?

with version do you use.. 
I don't have this problem at non of my sites.

Version 6.1.6

strange, 
is there something changed on the server, or has your hoster changed something.. you never now.

also check your database admin table if there is something changed.. or empty.

I'm actually online with my host now and they're looking into it.   I've read other posts with the same problem and the answer only seems to be reinstall.  I REALLY do not want to do that.

maby only overwrite the admin map with the 6.1.6 installation admin map... its possible that there is something missing.. 
Its always possible .

Overwrite the Admin map?  How do I do that?

I asked my host to go to a back up file and database backup.  That seemed to fix the problem.  I can now login to admin.  Still not sure why this all happend.  So if anyone has the same problem, ask you host to go to a backup file before reinstalling.

I advise alway's if you have a dedicated or VPS to make a daily backup and a server backup every month.
If there is something wrong you can go direct back to the leatest backup.

HASH MD5

EXAMPLE:   Database
--
-- Dumping data for table `Admins`
--

INSERT INTO `Admins` VALUES ('admin-Username', '36cdfPASSWORD4rt5e4rzffc7dgf54fg5489gr4r54r');

Décryptez votre HASH MD5 instantanément

create Backup dolphin, ftp, mysql, ect.. !!!

Go to the PHPMYADMIN:

1/EXECUTE IN PHPMYADMIN - Mysql:


REPLACE INTO `Admins` VALUES ('admin', '81dc9bdb52d04dc20036dbd8313ed055');

Go to the admin dolphin:

your USER:              ADMIN

your PASSWORD:     1234

Its good ?