10.1.2 trial blank activities window

Just installed 10.1.2 as a trial from 9.3 on an MBA. I have 3 catalogues open and when 10.1.2 opens I see the Loading "Cat 1", "Cat 2" etc. However every time the last cat is loaded the activities window opens but is blank i.e. no number of images or what its doing other than an italic lower case i in brackets. The progress bar progresses to the end and then clears. If I click on a different folder the activities window re-appears and progresses again. I think it is creating previews as the time it takes to progress differs depending on number of images in folder, but it happens every time I open COP as if its not flagging previews as created.

Does anyone have and suggestions?
Robin