To transfer System 36 files using Data transfer in Client Access Express. Create a file description (DDS) with just one field called F00001 the length of one record. Create the file. Copy in the records from the original file and the transfer should work.
If the file has a key field you need to create a field K000001 the length of the key and another F00001 for the remainder of the record length. This enabled us to use existing data transfers from old DOS versions of Client Access in Express.