(About 3:25 pm)

I'm getting this error.

Unable to connect to Oracle Server.

Error:

 Connection refused(DESCRIPTION=(TMP=)(VSNNUM=153092352)(ERR=12500)(ERROR_STACK=(ERROR =(CODE=12500)(EMFI=4))(ERROR=(CODE=12560)(EMFI=4))(ERROR=(CODE=530)(EMFI=4 ))(ERROR=(BUF='32-bit Windows Error: 2: No such file or directory'))))

or 

ORA-01017: invalid username/password; logon denied

on every shut down oracles. 

I restarted the APM and Oracle process got shutdown again. (Tried several times and there were disasters due to the Oracle downs)

Since I could not let critical Oracles to down, I killed the APM service and re-installed. And it works. 

I do not know what was the problem (Or how it could happened, but it happened!).