TestComplete 12 is doing this to me, as well. Have you found any solutions?
Does it always run slow or is it an intermittent problem?
Is it always the same test or does it run slow in different places?
Have you checked to make sure that you don't have more than one copy of your application running?
Do you have other applications running on the same machine that you don't need for testing?
This seems to happen particularly when accessing the name map, or on the name map. It's intermittent elsewhere.
Does TestComplete freeze when you open the name mapping or does it take a while to open? How long does it take to open?
Viewing the name map seems fine, but if I try to edit a mapped object, (even right-clicking it), the whole program is down for the count. I wait several minutes (3+) before it's usable again. The same thing happens if I attempt to use the "highlight on screen" from the name mapping view.
