No error information when batch fails to upload to wikidata-test

[rajun274]

Content I've attempted:

qid,Len,Den,P31,P170,P1476,P571,P276
,Il Penseroso,Watercolour painting by Julian Rossi Ashton,Q18761202,Q6306955,"en:""Il Penseroso""",+1894-01-01T00:00:00Z/9,Q63468534

I tried uploading this content to "Wikidata-test" and it failed. There's no information as to why it failed, or how I could continue debugging my issue. Screenshot:

When I hover over the red "error" text, the tooltip only has empty curly braces "{}". (Note that this same content was successfully uploaded when I tried "Wikidata" instead.)

[VDK]

The issue is that the error is hidden in a hover on the exclamation mark. This is bad accessibility. It's completely inaccessible on a touch screen.