How can I expedite the I-526 process when the NVC has not received my case file a year after approval?

You need to communicate with both, the NVC and the USCIS, to get this resolved.

If the USCIS has not sent over the case, you may try submitting an e-request to the USCIS, or try calling the Customer Contact Center. The I-864 requires a filing fee, but that is used to move cases to the NVC. The Department of State says they are making files for cases received from the USCIS as recently as Jan. 5, so this seems like more of a USCIS problem than an NVC one.

You will need to contact the USCIS to have your case file transferred to the NVC. The email address is uscis.immigrantinvestorprogram@uscis.dhs.gov. Occasionally, files get lost so you may need to follow up with the USCIS and the NVC regularly to resolve the issue.

Request the IPO to transfer it and request the NVC to transfer it, and maybe reach out to your congressman.

Your attorney should be sending a bi-weekly email to the NVC and the USCIS. The transfer of cases has slowed down, but not to 11 months.

You can inquire into it with the NVC via their askNVC email. They should be able to research, find the file, and request the USCIS to send it to them.

File a mandamus lawsuit. It takes several months normally, but a year is too long.

Contact the NVC and/or get an attorney to assist you. They should be able to locate it and request it from the USCIS. If your approval never mentioned the NVC, then you may need an I-824.

Have you asked the lawyer who handled your case? He or she should be able to shake it loose. If that does not work, your senator can help.