Update troubleshoot.md

Author: Diego-Perez-Botero

articles/internet-analyzer/troubleshoot.md

@@ -13,15 +13,20 @@ ms.author: dibotero
 
 This article contains troubleshooting steps for common Internet Analyzer issues.
 
+## Things to keep in mind
+- The client script must be embedded into an **HTTPS** website. Measurements won't be collected if the script runs in a plaintext (**http://**) or local (**file://**) website.
+- Measurement data will only be collected if the Internet Analyzer profile's client script has been embedded into an application that is receiving real user traffic. Synthetic traffic (for example, Azure WebApp Performance Tests) does not typically execute embedded Javascript code, so no measurements will be generated by that type of traffic.
+
 ## Azure Portal
 **"A scorecard hasn't been generated for the selected filter combination" in the Scorecards section**
 
 Note that:
 - Scorecards are generated on a daily basis (at the end of every day, UTC time).
 - Scorecards are only generated if more than 100 measurements were collected for the selected filter combination (Test, Time Period, Country, etc.).
-- The client script must be embedded into an **HTTPS** website. Measurements won't be collected if the script runs in a plaintext (**http://**) or local (**file://**) website.
-- Measurement data will only be collected if the Internet Analyzer profile's client script has been embedded into an application that is receiving real user traffic. Synthetic traffic (for example, Azure WebApp Performance Tests) does not typically execute embedded Javascript code, so no measurements will be generated by that type of traffic.
-- Time series are generated once an hour, so you’ll need to wait at least that amount of time for new measurement data to show up.
+
+**"Total Measurement Count" is zero for one or both endpoints in a test**
+- Time series and measurement counts are computed once an hour, so you’ll need to wait at least that amount of time for new measurement data to show up.
+- Internet Analyzer only counts successful measurements (i.e., HTTP 200 responses) for its analysis. If one or both endpoints in a test are unreachable or returning a non-200 HTTP code, they will show up with zero total measurements.
 
 ## Next steps
 Read the [Internet Analyzer FAQ](internet-analyzer-faq.md)