QGIS » QGIS Application

I ran the Merge vector layers algorithm on three multipolygon polygon shapefiles. The algorithm completely failed to create a merged layer. The log is as follows:

Processing algorithm…
Algorithm 'Merge vector layers' starting…
Input parameters:
{ 'CRS' : None, 'LAYERS' : ['C:/Users/CRRGIS/Documents/GIS DataBase/CRCWMA/Area Controlled - Group Workday at Valley View.shp','C:/Users/CRRGIS/Documents/GIS DataBase/CRCWMA/Area Treated Detail 2015-16_normalized.shp','C:/Users/CRRGIS/Documents/GIS DataBase/CRCWMA/Combined CWMA Area Controlled 2012-2014.shp'], 'OUTPUT' : 'memory:' }

Taking destination CRS EPSG:3734 from layer
Setting output type to MultiPolygon
ID field in layer Combined CWMA Area Controlled 2012-2014 has different data type than in other layers (Integer instead of Integer64)
Execution failed after 0.12 seconds

Loading resulting layers

Algorithm 'Merge vector layers' finished

This is inconsistent with the algorithm description, which says

If attributes tables are different, the attribute table of the resulting layer will contain the attributes from all input layers. New attributes will be added for the original layer name and source.

It seems like QGIS should be able to combine an integer field with an integer64 field, but even if it can't it should still merge the layers, and put the incompatible attributes in two separate ID fields, renaming one of them if necessary.