When the OnePlus One debuted, potential customers were forced to take part in an invitation system and hope that they would be selected to purchase the phone. The second phone from OnePlus called the OnePlus 2 followed with an invitation system, but the company promised it would be a much smoother process and there would be plenty of invites available, Phone Dog reports.

When the OnePlus 2 was announced, the invite system for the OnePlus One ended and sales were open to the public. With the release of the OnePlus 2, this invite system is open for the new device and it is experiencing issues already.

OnePlus 2 is apologizing for OnePlus 2 buyers who have been forced to wait weeks for their phones to ship due to supply issues. 

OnePlus co-founder Carl Pei released a long apology on the OnePlus forums. Pei says he is sorry for letting down the buyers.

We simply messed up again and apologize for that," Pei says, adding that "hardware is extremely hard" and that there are a lot of factors to account for when shipping a phone.  

Pei says OnePlus will not be making promises like they did for the OnePlus 2. The OnePlus 2 launched August 11, but is just now shipping in large quantities to buyers.

Pei wants to make the OnePlus 2 open to more buyers. To do this, OnePlus will open up sales of the OnePlus 2 to the public for one hour in late September or early October. Hopefully, this does not lead to a website crash due to heavy demand.

Five million people have already preordered the OnePlus 2 and many of them are still waiting to get their device, Phone Arena reports.

The OnePlus One was a very popular smartphone due to its affordable price and many features. The invite-only system has been heavily critcized though.