The message "Exposure cannot be increased due to client configuration" can be linked to different causes.
Please check if you have received notifications from Saxo Bank about Renewal of personal details by e-mail or on the platform (Go to the envelope icon and click Inbox).
If yes, then please follow the instructions to submit the requested details, as that could be a reason you cannot open new positions and increase the exposure.
If this is not the case find out more here Why has my order been rejected?