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Common errors

Purrchiver tries hard to give you a specific, actionable error message for every failure case — not just “extraction failed.” This page is the catalog: every error you might see, what it means, and what to do about it.

If you hit something not on this page, email corey@purrchiver.app — I’ll add it.

Opening errors

“This file is a Windows installer (.exe), not an archive.”

You tried to open a .exe file. Windows installers aren’t archives in the relevant sense — they’re executable programs that, when run on Windows, install software.

What to do:

  • If you wanted the installer’s contents (e.g., to extract files embedded inside), use a Windows VM or a tool specifically for unpacking installers (Universal Extractor, 7-Zip on Windows). Most modern Windows installers (.msi, NSIS, Inno Setup) can be unpacked by specialized tools — Purrchiver isn’t one of them.
  • If you got the .exe by mistake (someone meant to send you a .zip), ask them to re-send.

“This file looks like a disk image (.dmg).”

You tried to open a .dmg. Disk images are mounted by Finder, not extracted. Double-click the .dmg in Finder and macOS will mount it as a volume.

(v1.1 may add an “Open DMG” workflow in Purrchiver that mounts the DMG and copies the contents to a folder. For now, Finder owns this.)

“This file appears to be a StuffIt archive (.sit / .sitx).”

See the dedicated page: StuffIt files.

Short version: StuffIt is an abandoned format. Use The Unarchiver (free from the Mac App Store) for the one-time extract.

“This file’s header doesn’t match any format Purrchiver recognizes.”

The file isn’t an archive Purrchiver knows about. Possibilities:

  • The file is corrupt — try downloading it again.
  • The file is an unsupported format — see Format support for the list of skips.
  • The file has the wrong extension — .zip could actually be a renamed .tar.gz, etc. Try opening in another tool to confirm.

“Couldn’t read filename — permission denied.”

macOS denied Purrchiver access to the file. Either:

  • The file is in a protected location (Documents, Desktop, Downloads, iCloud Drive) that needs explicit per-app access.
  • Fix: Open System Settings → Privacy & Security → Files & Folders, find Purrchiver, and grant the relevant folder access.

If the file is somewhere unusual (a network mount, external volume with write protection, etc.), Purrchiver may still get denied even with permissions granted. Try copying it to your Desktop first.

Multi-part errors

“Missing parts in folder: archive.part04.rar”

You opened a multi-part archive but Purrchiver couldn’t find one or more parts. The missing filename(s) are listed specifically.

What to do:

  • Find the missing part(s) and put them in the same folder as the part you opened.
  • Re-open the archive (any part).

See Multi-part archives for how multi-part opening works.

“Multi-part archive is out of order.”

Purrchiver found the parts, but the part numbers don’t form a complete sequence (e.g., .part01.rar, .part02.rar, .part04.rar — missing 03).

Same fix as above: locate the missing part(s).

Password errors

“Incorrect password. Try again.”

The password you typed doesn’t decrypt the archive. Either:

  • Typo — type it again. Check Caps Lock.
  • Wrong password — confirm with whoever sent you the archive.
  • The archive’s encryption is broken / corrupt — try opening it in another tool (7-Zip on Windows, 7z x on Linux) to confirm.

Purrchiver cannot recover passwords. There is no “forgot password” feature.

“This archive has header encryption — Purrchiver needs the password to even list its contents.”

For 7z and RAR with header-encrypted entries, the filename list is itself encrypted. You can’t browse the contents until you provide the password.

This is normal for header-encrypted archives. Enter the password.

Extraction errors

“Archive is corrupt or truncated near entry X.”

The archive’s bytes don’t match what its metadata says they should be. Common causes:

  • Download was interrupted — re-download.
  • Disk error on the source — try copying the file again from its source.
  • Multi-part with a damaged part — try extracting the parts individually to confirm which one is damaged; re-download just that part.

If Purrchiver was partway through when it hit the corruption, the entries it had already extracted are intact in the destination.

“Couldn’t write to destination — permission denied.”

macOS won’t let Purrchiver write to the chosen folder.

Fix: Either pick a different destination, or grant Purrchiver access to the parent folder in System Settings → Privacy & Security → Files & Folders.

“Disk is full.”

Free up space and try again. Purrchiver shows how much space the extract needs in the toolbar before starting (if it can calculate it from the archive’s metadata).

“Filename too long for filesystem.”

The archive contains a filename longer than the destination filesystem allows (e.g., FAT32 caps filenames at 255 characters; some legacy filesystems cap shorter).

Fix: Extract to a different filesystem (your APFS Mac startup disk, not the FAT32 USB drive).

“Path contains invalid characters for filesystem.”

The archive contains characters in filenames that the destination filesystem doesn’t allow (NTFS forbids < > : " | ? * in filenames; FAT32 disallows even more).

Fix: Extract to your Mac’s APFS startup disk first, then move the files where you actually want them. (Entry-rename in Edit mode isn’t in v1.0 — see Editing an existing archive — so for now the APFS-first workflow is the answer.)

Creating errors

“Passwords don’t match.”

The two password fields in the Create Archive sheet have different text. Re-type one to match the other.

“Output filename already exists. Replace?”

Purrchiver won’t silently overwrite an existing file. Confirm to replace, or change the output filename.

“Couldn’t write to output location — permission denied.”

Same as the extraction equivalent. Pick a different location, or grant Purrchiver access in System Settings → Privacy & Security → Files & Folders.

“Archive verification failed.”

Purrchiver tried to verify the archive it just wrote, and the verify failed. The unverified archive is saved with the suffix .purrchiver-unverified so you can inspect it. Your source files are unaffected.

This is rare. If it happens, please email corey@purrchiver.app with:

  • The format you were creating
  • Whether encryption was on
  • Whether split-volumes was set
  • Roughly how large the source files were

Editing errors

“Original archive was modified by another tool while you were editing it.”

Purrchiver detected that the underlying archive file changed between when you opened it and when you tried to save. Probably another tool modified it, or the file was synced from cloud storage while you were editing.

Fix: Close Purrchiver’s edited copy (discard changes), re-open the archive, and make your edits again. Purrchiver protected the original by not blindly overwriting.

“Cannot modify a read-only format.”

Purrchiver can read RAR, .deb, .rpm, XIP, PKG, MPKG, IPA, XAR, .cab, .lha, .warc, .Z, and CPIO (in some configurations), but cannot write or modify them.

Fix: To “edit” one of these, extract everything to a folder, make your changes, and create a new archive (probably as ZIP or 7z).

Other

“Not enough memory to load this archive’s index.”

Some archives have enormous file lists (1M+ entries). Purrchiver caps the in-memory entry list at 1M entries to keep memory predictable.

Fix: If you’re hitting this, the archive is unusually large. Email corey@purrchiver.app with the archive size and entry count if you can determine them — we want to know about real-world cases.

“Operation cancelled by user.”

You clicked Cancel during a long operation. Any work partially done is left in place; nothing is rolled back automatically.

For extractions: files already written are kept. For compresses: the partial output file is deleted (you don’t want a half-written archive). For modifications: the original archive is untouched (the rewrite hadn’t finished and verified yet).

How to report a bug you don’t see here

  1. Open Console (Spotlight → Console).
  2. Pick Crash Reports in the sidebar (if Purrchiver crashed) OR filter for “purrchiver” in the search field (for non-crash logs).
  3. Email what you find to corey@purrchiver.app along with:
    • macOS version
    • Purrchiver version (Purrchiver → About Purrchiver)
    • What you were doing when the problem happened
    • What you expected vs. what happened

Email goes directly to me. There’s no support queue, no chatbot.