What do you mean?
There was a two state solution from the beginning.
Israel and Jordan.
Actually the Palestinian Mandate only mentions the establishment of a home for Jews. Great Britain took three fourths of the mandate and gave it to a Saudi prince and established the Emirate of Transjordan (meaning East of the Jordan).
What was once a one state mandate became a two state fact (Transjordan-Jordan and everything west of the Jordan for a Jewish homeland). Everything that has happened since that time has been Arab Muslim armed attempts to wipe the Jewish people out, and take the area west of the Jordan.
The PLO (PA) actually believe that they own all of what is present day Jordan and Israel along with the West Bank area.
So, Arabs have never accepted a two state solution, and what the world in general calls a two state solution is actually a three state solution (Israel, Jordan, and “The West Bank”). Currently there are sour areas (Israel, Jordan, the West Bank, and Gaza).
The only occupation occurring in the the area of what is called the Palestinian Mandate was by Transjordan, when it invaded and occupied the area called the West Bank between 1948 and 1967. Since 1967 Israel been in possession of the area meant for their state after the British gave three fourths to the Saudi prince.