Hi Kamelek,This should be possible.It would be highly recommended to upgrade to min 5.8.6.5 ideally 5.8.6.9If you are still seeing issues we would need a sample config from the AP7522 and AP6532
Morning Bernard, You can upgrade direct from 5.x to 7.7.1.9 code for APs. The only concern may the the VX900, see article below.https://extreme-networks.my.site.com/ExtrArticleDetail?an=000060688