After install QGIS Madeira on a new Win10 PC, QGIS crashes when exporting a PNG file, the crashlog:
QGIS Info QGIS Version: 3.4.10-Madeira QGIS code revision: 3d97aaae88 Compiled against Qt: 5.11.2 Running against Qt: 5.11.2 Compiled against GDAL: 2.4.1 Running against GDAL: 2.4.1 System Info CPU Type: x86_64 Kernel Type: winnt Kernel Version: 10.0.18362
After that, I have installed QGIS Essen, that can only export maps as PNG file with max. 12% free RAM usage and max. 115dpi.
In conclusion, I will advise all people, do not spend cash for QGIS to print large maps, because at this time QGIS on WIN10 is unable to export large maps as PNG.
Meanwhile I have solved partially the problem. When QGIS Essen run as administrator on win10, then I are able to make PNG file with only max. 115dpi, but not more. The filsize is is 64MB (PNG): that is ridiculous.
Conclusion: the memory allocation warning from QGIS is partially necessary, and partialy a reason from the QGIS programmer to fake the user.
Unfortunately are max. 115dpi not enough for my maps, because they content also very small lines and character, and these lines and character become blured with 115dpi. If a developer will solve this, I am able and willing to help him.