What can an investor do if an EB-5 regional center changes its business plan?

As long as any changes are "immaterial," it should not cause any problems. Otherwise, you may have to resubmit the I-526.

If there is a material change to the business plan after the I-526 petition is filed, then the EB-5 investor may have to refile the I-526 petition with the new business plan. This will definitely be the case if there is a material change before the conditional permanent residency is approved.

If the new business plan is accepted and the RFE response is timely, such factors would not cause an I-526 petition to be rejected or denied. Depending on your agreement, you could possibly withdraw your participation.

It will depend on whether or not the change is considered a "material change" by USCIS. You should contact the regional center to explain what the change is. You may need to employ your own attorney to represent you regarding the regional center.

As long as the business plan changes are not considered "material changes," there should be no problem. If the only changes are the number of investors and timing issues, these changes are not likely to be considered material. If the business plan changes affect the entire scope and industry of the business activities, then that might present a problem. It is unlikely that a regional center would make such drastic changes, but if you are still concerned, you should consult with an experienced EB-5 immigration attorney who is independent from the regional center (to get a second opinion).

If the business plan change is considered material there will need to be a new I-526.

The only thing that you could do is hope that the new business plan meets the muster of increased requisite job creation based on the increased number of investors - I am assuming that USCIS would not have issued the RFE if the number of investors actually were reduced. You could review whether you could withdraw from that investment and reinvest into another regional center project. The subscription agreement and the limited partnership agreement will set forth options if the application may be denied what you are able to do. Increasing the number of investors and changing the business plan after I-526s were filed is not a good idea as it puts the previously filed investors at a precarious position like this.

Changes to the business plan may have caused an RFE if that changed business plan was provided to USCIS through an investor who filed after you. USCIS may package I-526 petitions for a single new commercial enterprise. If the changes to the business plan address the issues in the RFE, then the response should include that. If the RFE was issued because of the changes, however, you may need to refile.