Excel ran out of memory — not enough resources to open the file

What this looks like

A dialog interrupts the open or a recalculation with wording like “Excel ran out of resources” or “not enough memory to complete this action,” sometimes followed by Excel freezing, closing, or reopening with a blank or partially-calculated sheet. It can happen on files that don't look especially large, especially ones with heavy formatting, large formula ranges, conditional formatting, or pivot caches.

Why it happens

This isn't your system's total memory — it's Excel's own ceiling. Opening a workbook means building a full object model of every cell, style, and formula dependency, then recalculating anything volatile. Large formula ranges, whole-column references, heavy conditional formatting, and pivot tables all multiply the memory Excel needs well beyond the file's size on disk, and Excel hits its own limit before your machine hits its.

What you actually want

The values in the workbook, not a working Excel session. xlsx-for-ai reads the file's data directly — it doesn't rebuild Excel's calculation engine, recompute formulas the way Excel does, or hold the whole styled object model in memory — so it can extract sheets, columns, and rows from a workbook that trips Excel's own resource ceiling, and hand you the data or a converted file instead.