I ran the Aperture plugin importer (via Lightroom 5.7.1) but it failed to copy a large number of seemingly random files over (which wasted hours of re-organization before I realized).
Are there limitations to the number of files imported due to resource starvation? Workarounds?
Adobe is advertising LightRoom as an Aperture replacement in their marketing but they're failing to import the files. This is quite aggrevating.
This just happened to me, too. I decided to split the aperture library into years, and import them one by one. 2015, a partial year, worked well, but 2014 was a disaster. Many files were omitted.
The log (in Documents, on my Mac) includes about 1200 entries such as
Failed to import /Users/friedman/Desktop/ApLib2014albums.aplibrary/Masters/2014/07/25/20140725-205903/2014 0702_085734-X20.jpg. (Possible reasons include asset offline or unsupported asset type.)