Most file errors show up in one of two places: instantly in the upload zone (before the file even leaves your browser), or shortly after upload during the Reading your file stage. Every error below has a straightforward fix.
"File exceeds the 50 MB limit"
Cause: The file is larger than the 50 MB per-file cap.
Fix: Shrink or split it. Excel files bloat easily; re-saving as CSV often cuts the size dramatically. For scanned PDFs, split the document into parts. If the file is big because it has too many rows, see the row-limit section below. Details in Supported file types and limits.
"Unsupported file type. Accepted: .csv, .xlsx, .xls, .tsv, .pdf"
Cause: The file's extension isn't one of the five accepted formats. Common offenders: .numbers (Apple Numbers), .ods (OpenOffice), .txt, .zip, and image files like .jpg photos of a price list.
Fix: Open the file in its native app and export to CSV or XLSX. For a photo of a price list, save it into a PDF and upload that. See PDF price lists.
File content doesn't match its extension
Cause: The file was renamed rather than converted, for example an Excel file renamed from .xlsx to .csv, or a PDF renamed to .xls. Renaming changes the label, not the contents, and the mismatch is detected during reading. The error mentions the file "was detected as" a different format and suggests it may have been renamed.
Fix: Open the file in its original application and use Save As / Export to produce the format you want. A real conversion rewrites the contents; renaming never does.
File "could not be identified": empty or corrupt
Cause: The file is truncated, damaged, or zero bytes. This usually happens with an interrupted download from a supplier portal or an email attachment that didn't fully save.
Fix: Re-download the file from the source and confirm it opens cleanly on your own machine before uploading. If your supplier sent it, ask them to resend.
Too many rows
Cause: The catalog exceeds the 50,000-row limit.
Fix: Split the file into pieces (by category, brand, or halves), keeping the header row at the top of each piece, and upload each as its own catalog. See Large catalogs and grading times.
Password-protected files
Cause: The spreadsheet or PDF requires a password to open, so its contents can't be read.
Fix: Open the file with its password, then save an unprotected copy (in Excel: File → Info → Protect Workbook → remove the password; most PDF tools have a similar "save without security" option) and upload that copy.
Still stuck?
If a file fails during reading, check its error on the catalog page; see Fix a failed or stalled catalog. If these fixes do not resolve it, contact Support with the catalog name and the error you see.