In MicroStation you now can attach an iTwin as the Collaboration tools and attach an iModel as a reference in a DGN. Sometimes when attempting use the Attach iTwin tool you will get and error message that says, "Fail to Update ITwin [Project Name] Project Information Model" and you are unable to do the attachment.
There is a possibility that you have a corrupted iModel on your disk drive.You can try deleting the folder ‘C:\Users\[User Name]j\AppData\Local\Bentley\' delete the 'iModelAttach’ folder and try again to attach.
If this does not resolve the issue, please log an issue with the product team that you are having the problem. You can send them the log files from this folder, 'C:\Users\[UserName]\AppData\Local\Bentley\Logs\"
These log files will be titled, ‘iModel02FileIO.log’ along with ‘ITS-FileIOBackendxxx.log’ (The name will include the date of attempt to attach iModel).
These files might be helpful in determining the cause of the issue.
New in MicroStation CONNECT Edition Update 17 – AEC Transform and improved UI for iTwin Attach workflows