We apologise for the issues you may have been experiencing with placing a click-and-collect order. When this error pops up it will mean that your details under your account are not correct. Even though you are collecting in-store your account address details need to be finalised.
If you can log in, go into your account and under your address there may be a postcode or state missing, once this is rectified the order will flow through. 
Have a wonderful rest of your day and please do not hesitate to contact me if any further assistance is needed.
Merci,
L'Occitane en Provence