I'd like you to try a system clean up and a fresh installation of 16.6.2, to see if it resolves the issue.
1. Run the Windows self check tool to check scan and automatically repair any corrupt files found in Windows. There is a guide on how to do it here. What you need to do is run an elevated command prompt (elevated means run it as administrator) and type SFC /SCANNOW. This will generate a statement indicating if errors were found the Operating system and if they were fixable.
3. Update Windows. Install all available critical, recommended and optional updates. Often Netframework and Visual C are included in the recommended or optional updates Windows provides. Windows should always be fully up to date before installing our drivers!
4. Use DDU to sweep the system of AMD drivers in safe mode.
5. Install the latest Crimson 16.6.2 drivers once the above is completed and check to see if the issue is resolved.
I just completed all of the steps you asked to me do and it appears to still be happening. I have been trying to figure out exactly what causes it but I have been unable to find a way to recreate it. Sometimes it will happen the first time I open wattman, but other times it won't happen for hours. It does seem though that it happens most commonly after running something gpu intensive and then trying to open wattman after. For example if I run a benchmark and then open wattman after to check temperatures it is very likely to stop responding.
this is exactly the same issue I'm having
Faulting Application Path: C:\Program Files\AMD\CNext\CNext\RadeonSettings.exe
Problem Event Name: APPCRASH
Application Name: RadeonSettings.exe
Application Version: 10.1.1.1633
Application Timestamp: 577c6e5b
Fault Module Name: Qt5Gui.dll
Fault Module Version: 126.96.36.199
Fault Module Timestamp: 558c6cb7
Exception Code: c0000005
Exception Offset: 0000000000017390
OS Version: 10.0.105188.8.131.52.256.48
Locale ID: 1033
Additional Information 1: 35ed
Additional Information 2: 35ed3724bb3041b323369e6246c127d8
Additional Information 3: 2373
Additional Information 4: 23735e464a77b7eccc6c1e2b10e98268