There appears to be a regression starting in build 2015.1.415. When you go to view the data in the Details view of a Performance test, no data shows up. Apparently the data is stored... if you downgrade to 2015.1.319 the data for the test run in 2015.1.415 now appears. See attached screen shot for comparison examples. Here is what the application log for 2015.1.415 contains:

[05/20 12:07:20,Telerik.TestStudio.exe(73080:1),Performance] PerformanceBlendedSampleDataViewModel.GenerateVisiblePerformanceCounterSamples() : 0 out of 0 series mappings were generated for the performance counter graph in the visible time range.
[05/20 12:07:20,Telerik.TestStudio.exe(73080:1),Performance] PerformanceMainViewModel.set_ActiveProfile() : ActiveProfile viewmodel replaced.
[05/20 12:07:26,Telerik.TestStudio.exe(73080:1),TestStudio] ProfilerResultsFile.get_HttpTrafficProfilerConfiguration() : Error loading HttpTrafficProfilerConfiguration from tsperf file, defaulting configuration
[05/20 12:07:26,Telerik.TestStudio.exe(73080:1),Performance] PerformanceBlendedSampleDataViewModel.get_VisibleHttpTrafficEventViewModels() : 66 out of 66 HTTP events now fall within the visible time range.