Only some files added — batch limit
When adding files to an existing queue, only some were accepted. Product text: “Only {added} file(s) were added; each batch is limited to {maxBatch} file(s).”
Why this happens
Each plan has Max items per upload (ul2_max_batch_*). Room left in the queue is maxBatch − currentQueueLength. Extra files from the picker or drag-drop are dropped. This is a soft limit message, not a server crash.
Diagnose and fix
1. Member: upload what is queued, clear finished items, then add the rest in another batch — or select fewer files at once.
2. Admin → Settings → Users & limits → Max items per upload (ul2_max_batch_reg / _prem / _prem_pro). 0 = unlimited (capped in code).
3. Per-user override if one account needs a higher batch size.
4. Do not confuse this with File upload slots (ul2_slots_*) — that controls parallel transfers, not how many files sit in one batch.