Why do I get 'e_PDFA2_3_3_1: Device-specific color space used, but no GTS_PDFA1 OutputIntent' when using PDF/A Compilance?

Q: Hi, i got a problem using PDFACompilance, after a do a validation
for PDF/A (with other software), i get a result:

e_PDFA2_3_3_1: Device-specific color space used, but no GTS_PDFA1
OutputIntent (Objects: 6, 309, 553)

What can i do to get rid of this problem?
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A: The most likely problem is that color management is not enabled. To
fix this simple call PDFNet.SetColorManagement(PDFNet.CMSType.e_lcms)
after initializing PDFNet - along the lines of PDFATest sample
project:
  http://www.pdftron.com/pdfnet/samplecode.html#PDFA