Try each of the following steps in order until the issue is resolved:
  1. Ensure the project has not been deleted and exists in The Financial Edge.
  2. On the Fund GL Distribution Tab, ensure that the correct Project is selected for each gift type.
OR

Run the Update Accounts Plug-in.

Note:  The Gift ID referenced in the error is the System Record ID.  Query on the System Record ID to locate a specific Gift record.