When you converted images into searchable PDF files with the [Embed text information in a PDF file] checkbox selected, if a message is displayed, indicating that "Could not perform the recognition process.", check the following:
A computer that you are using may have insufficient memory
The "Could not perform the recognition process." error may be displayed when the file size of scanned images which you converted into searchable PDF files is larger than the size that the memory of the computer can process.
Reduce the PDF file size by splitting an image into multiple ones or by deleting unnecessary pages from an image, and then convert the image into a searchable PDF file again.
For details about creating a multi-page image from pages of another multi-page image or deleting a page, refer to ScanSnap Help.