I have seen this issue a few times before and what we were dealing with then is that the password that was associated with the project was for some reason different than the one that was associated with the bulk of the projects and not allowing the connection to the DB to be created to restore the project correctly. I am guessing that may be a similar issue here as the project in question was inactive on the prior server and it is possible that the passwords were changed after this project was deactivated and the project has a different password than the others.
What we have attempted in the past is to have the password reset on the DB schema for this project. I would suggest having it changed to the same one that the other projects are using. If unsure the default password is tdtdtd and I would suggest starting there. In the past we had the DBA change the schema to that password and then afterward change the password within the dbid.xml to the encrypted version of this (assuming this is the password the encrypted one would then be the same as the other projects have displayed, or you can create a new blank project and gather the information from that project.
After this attempt to restore the project and if this issue persists then the password is different than the one associated with the other projects. At this point you would want to insure that the password assigned to the project DB schema is what you thought it was and then you can enter it directly into the dbid.xml where the password is stored in clear text, just make sure to preclude it with the prefix TXT: and then enter your password in clear text and reattempt the restoration.
These steps have always worked for me in the past when this issue was arisen. I would suggest these actions and if that fails then you may want to contact your support group and open a case for the issue with them.
Hope this helps,