Data Load Failure

I have a delta load scheduled to the cube via process chains. The load failed due to invalid characters. I deleted the request from the cube. Now when I go to the Infopackage and try to load only the PSA it doesnt allow me to. Previous it loaded deltas only to data targets.

It says "Last delta update is not yet completed Therefore, no new delta update is possible. You can start the request again if the last delta request is red or green in the monitor (QM activity)"

How do I load the data to PSA and then make changes to the reocrds manually.

It doesnt allow me to load data giving the above message.

Thanks in advance