web_statistics_executor.exe task failed: The system cannot find the file specified. (Error code 2) at RegQueryValueEx valueName=AWStatsPath

Symptoms

Daily web statistics analyzers run task ( web_statistics_executor.exe ) in Tools & Settings > Scheduled Tasks fails with the following error:

PLESK_ERROR: Task "C:\Program Files (x86)\Plesk\admin\bin\web_statistics_executor.exe" completed with error in 1 seconds, output:
The system cannot find the file specified. (Error code 2) at RegQueryValueEx valueName=AWStatsPath

Only Webalizer is listed as Web Statistics component in Tools & Settings > Server Components :

Cause

AWStats installation is corrupted: Daily web statistics analyzers run task is calling AWStats, but actually it is missing in Plesk

Resolution

Install AWStats in Tools & Settings > Updates and Upgrades.