Page "Zohar" Paragraph 117

Despite the preeminence of Tikunei haZohar and despite the topmost priority of Torah study in Judaism, much of the Zohar has been relatively obscure and unread in the Jewish world in recent times, particularly outside of Israel and outside of Chasidic groups.

Although some rabbis since the Shabbetai Tzvi debacle still maintain that one should be married and forty years old in order to study Kabbalah, since the time of Baal Shem Tov there has been relaxation of such stringency, and many maintain that it is sufficient to be married and knowledgeable in halakhah and hence permitted to study Kabbalah and by inclusion, Tikunei haZohar ; and some rabbis will advise learning Kabbalah without restrictions of marriage or age.

In any case the aim of such caution is to not become caught up in Kabbalah to the extent of departing from reality or halakhah.