Passwords do not work after migration

[maury1971]

Well i installed  new verion 1.2.1  on subdomain ,  i imported all data , customers , adresses  in the database .

at login ( user side )  password are not working, even if the MD5 key are the same in both Mysql tables , 
i suppose is related to the SALT key ,
should i replace the new SALT key with the OLD one ??
what about the UNIQUE ID , and ENCRIPTION KEY >>?


p.s. : previous version what 1.1.5 ..   so ENCRIPTION KEY was not existing in config file

please tell  me about just to avoid to make damages
tnx

[Basara]

Please backup then replace SALT key