Why does the "Order Cancelled - Whole order or its remaining part is cancelled." message appear?

[jdvest]

Morning all. Anyone know why it is not possible to place a "Limit" buy order on shares?

I am trying to place a Limit order on a London stock, and the error below appears

"Order Cancelled - Whole order or its remaining part is cancelled." 

Tried with an expiry of "Day" or "Good till Cancelled", same result.

Some screenshots attached, any tips would be helpful.

choose files... Click to choose files

 

Edited October 13, 2020 by jdvest
Added another screenshot

[HarbourMaster]

I hit the same problem today.  I had to contact Customer Support via their chat service.  The problem was that I set a limit price of 826.6 -- which is NOT a multiple of 0.50 GBX (penny sterling).  When I changed the limit price to 826.50, the instruction went through without problem.  In my humble opinion, they should have implemented the system in a way that give a more meaningfully error message, such as "Limit price must be in a multiple of 0.50 GBX"