Forum Discussion
Power BI Desktop: Query Not Fully Loading
All, after installing August desktop app AND August on-premises gateway, no more issues for me.
I stumbled upon this issue as well. It happened to me in two reports (identical in all aspects but some source tables for the data), one with ~25m records and the other with ~48m. Both reports import their data from SQL Server.
In an effort to find out what's causing it, I activated the tracing & crash dump logging options in the diagnostics settings, and came up with the following:
1. The source for the problem seems to be an issue with Microsoft.Mashup.Container.NetFX40 and/or Microsoft.Mashup.OleDbProvider.
2. When the issue occures, it is also logged to the windows application log. Some entries mentioned "OLE DB or ODBC error: Exception from HRESULT: 0x80040E4E", suggesting the connection to the server was cancelled.
3, Initially, I encountered some entries in one of the logs of which the specified action was "Engine/IO/Db/Microsoft SQL/ReportFoldingFailure".
4. Failing to find any useful info on the web, I decided it would not hurt to check if the issue was related to query folding. I therefore modified my queries so that query folding would not occur. It resulted in the issue being resolved in the smaller report, and replaced with new error in the larger one, with the following error message:
"Non-negative number required.
Parameter name: value"
5. Inspecting the logs generated from the larger report, I found thousands of entries referring to a "FileSystemAccessHelper/TryIgnoringAccessExceptions" action. Most of the exceptions were of type System.IO.EndOfStreamException, but a few were of type System.IO.IOException, specifying some cached files could not be accesses because they're open by another process.
6. Realizing this problem is bigger than me, I decided to try and get around it by creating the final form of the data table on the SQL Server side, thus removing the heavy workload (Which was mostly merge operations) from the mashup engine. This resulted in a successful report refresh.
Basically, it seems like we got a faulty mashup engine with the July 2018 release.
itayrom, great minds think alike... I too, am "doing it on the database". Still, this issue is obviously not normal. Will post here if support comes up with a resolution.