According to the NSF, it is migrating its business applications to a new platform from November 8 at 8:00 PM EST through November 12 at 6:00 AM EST.
"As part of this effort, NSF will also upgrade the alpha-numeric character set used by the FastLane and Research.gov systems to correct text errors, such as special characters displaying as question marks ("?") in proposals and project reports. This migration has been scheduled over the Veteran's Day holiday weekend to minimize the impact of the systems downtime on the research community and NSF staff.
During this outage, there will be no access to these websites, proposals cannot be submitted in FastLane or Research.gov, and project reports and cash requests cannot be submitted in Research.gov. However, previously saved information and uploaded documents in FastLane and Research.gov, including in-progress proposals and project reports, will be accessible after the migration is completed.