Hi Shatra
Well how did you find the problem was with the credentials table?
Did you try doing an mxexport before deleting the table and what error were you getting?
I see that you have deleted the credential database, was it using the sql management studio ?
Now the below error output which you have pasted, was it from the log file or from the mxexport output failure.
I see this a bit of complex situation at the moment.