My laptop (Lenovo x1) usually crashes When I add legend to a map composer in QGIS (QGIS 3.2 BONN). Problem is that all layers in the project will be "auto-updated" to the legend and this will get my laptop "stuck". Why is this "auto-update" box is pre-defined and checked. Of course this is dependant on your project size..but is there anyway to prevent this? i.e How to code "un-checked" auto-update box from the start?
Open a new, empty project. Add print composition, style it to your needs and when adding the legend, uncheck that box. Save the composition as a template and then use that template, whenever you need to create a map.
Also, you should remove the compositions from your project after having created a map, since loading compositions upon opening the project anew can result in significantly longer loading times.