Do not import GAX metadata using GA.
If you still would like to do so you will need to search for "prerequisite" attributes in the GAX metadata xml file (e.g. search for "prerequisite", example: prerequisite="READ_ACCESSGROUPS") and remove those attributes.
Check this: https://genesyspartner.force.com/customercare/pkb_Home?id=kA4U00000008gu8&q=metadata+GAX&l=en_US&at=SOLUTIONS__kav&fs=Search&pn=1