okToExtractText

Check to see if the PDF file allows text extraction.
[read-only property] okToExtractText([out, retval] VARIANT_BOOL *ok)
This function returns false if the PDF file is encrypted and does not allow extraction of text. The owner password can be used to circumvent this: if a valid owner password was supplied to loadFileWithPassword or loadStreamWithPassword, this function will always return true.

If this function returns false, the text extraction functions will not return any text.

VB6:
If Not pdf.okToExtractText Then ' can't extract text from this document ... End If