Query from PowerBI to AI suddenly fails with 502 Bad Gateway

Question

To retrieve data from Application Insights Analytics, we use a Power BI Query (M) in Power BI (Desktop). We uploaded the Power BI Report to Power BI Online and set it to update every day. It functioned properly until January 25, 2017, when it stopped working (UTC).

We got the following error:

DataSource.Error: Web.Contents failed to get contents from '.....' (502): Bad Gateway

This is the complete error:

DataSource.Error: Web.Contents failed to get contents from 'https://management.azure.com/subscriptions/<subscriptionId>/resourcegroups/fps.fsa/providers/microsoft.insights/components/4PS%20Field%20Service%20iOS%20-%20iOS/api/query?api-version=2014-12-01-preview&csl=customEvents%0A%7C%20where%20timestamp%20%3E%20ago%2830d%29%0A%7C%20order%20by%20timestamp%20desc%0A%7C%20extend%20dimensionUserId%20%3D%20tostring%28customDimensions.%5B%27userId%27%5D%29%0A%7C%20extend%20dimensionHost%20%3D%20tostring%28customDimensions.%5B%27url%27%5D%29%0A%7C%20extend%20measurementQuantity%20%3D%20iff%28%20isnotempty%28customMeasurements.%5B%27value%27%5D%29%2C%20todouble%28customMeasurements.%5B%27value%27%5D%29%2C%200.0%29%0A%7C%20extend%20measurementKey%20%3D%20tostring%28customDimensions.%5B%27key%27%5D%29%0A%7C%20extend%20platform%20%3D%20%27iOS%27%0A&x-ms-app=AAPBI' (502): Bad Gateway
Details:
    DataSourceKind=Web
    DataSourcePath=https://management.azure.com/subscriptions/<subscriptionId>/resourcegroups/fps.fsa/providers/microsoft.insights/components/4PS%20Field%20Service%20iOS%20-%20iOS/api/query
    Url=https://management.azure.com/subscriptions/<subscriptionId>/resourcegroups/fps.fsa/providers/microsoft.insights/components/4PS%20Field%20Service%20iOS%20-%20iOS/api/query?api-version=2014-12-01-preview&amp;csl=customEvents%0A%7C%20where%20timestamp%20%3E%20ago%2830d%29%0A%7C%20order%20by%20timestamp%20desc%0A%7C%20extend%20dimensionUserId%20%3D%20tostring%28customDimensions.%5B%27userId%27%5D%29%0A%7C%20extend%20dimensionHost%20%3D%20tostring%28customDimensions.%5B%27url%27%5D%29%0A%7C%20extend%20measurementQuantity%20%3D%20iff%28%20isnotempty%28customMeasurements.%5B%27value%27%5D%29%2C%20todouble%28customMeasurements.%5B%27value%27%5D%29%2C%200.0%29%0A%7C%20extend%20measurementKey%20%3D%20tostring%28customDimensions.%5B%27key%27%5D%29%0A%7C%20extend%20platform%20%3D%20%27iOS%27%0A&amp;x-ms-app=AAPBI

Does anyone know how to solve this?