Pokémon ROM patch checksum error?
Identify which file failed the check before changing your base game, patch or emulator.
Which message did you get?
| Message in our patcher | What to investigate |
|---|---|
| Wrong base file — patching stopped | The input size or CRC32 differs from the patch requirement |
| unfinished patch | An unfinished or structurally invalid patch file |
| The result did not verify | The patch or generated output checksum did not match |
| Result cannot be verified | An IPS patch without an embedded output checksum |
Other patchers can phrase errors differently. Record the exact message and whether it appears before patching or after output generation; do not treat every checksum message as the same failure.
UPS or BPS says your base file is wrong
- Read the creator's README for the exact base game, region, language and revision.
- Select your unmodified game file, rather than a ZIP archive, patch file or already patched adventure.
- For GBA, use the ROM checker to inspect the header's game identity and revision. Then return to the patcher's size and CRC32 comparison.
- If the expected and found values still differ, keep the original untouched and establish why it does not meet the developer's requirements.
A header label is a clue, not a complete-file integrity check. Two files with similar names or the same apparent game identity can contain different bytes. Likewise, matching file size alone is insufficient when CRC32 differs. Compare the same hash type: CRC32 and SHA-1 are different values, not interchangeable strings.
Do not patch one modified game repeatedly unless the creator explicitly documents that update path. A release patch may expect a clean base rather than last month's patched output. The creator's specific instructions settle that question.
The patch is unfinished or unsupported
Keep a record of the failing patch and obtain the intended patch asset again from the developer's release page. If the download is an archive, extract its contents and select the actual patch. An archive, a source-code bundle and a patch are different inputs.
Our tool supports IPS, UPS and BPS. It does not apply xdelta patches; follow the creator's tool instructions for that format. Renaming an xdelta file to .bps does not convert it. For the catalog's DS example, Renegade Platinum, follow the documented xdelta workflow.
Unsupported format and wrong base are different failures
“unrecognized format” means this tool did not identify supported patch contents. It is not the same as a recognized UPS or BPS patch reporting a mismatched source. Resolve the format and tool first; a different base cannot add BSP or xdelta support to this patcher.
| Selected name or package | What the name suggests | What still needs checking |
|---|---|---|
| A .bsp name | A format this tool does not apply | The actual creator package and its required tool; the filename does not identify a game |
| A .xdelta or .xdelta3 name | A separate patching tool | The maker’s required tool, base and order |
| A .zip, .7z or .rar name | An archive still needs extraction | The intended file and instructions inside |
| A .bps name with undocumented contents | A filename label only | Download completeness and real supported contents |
Our tool shows a filename-based next-step hint only after supported contents are not detected. A real BPS file with a misleading .bsp name is still identified by its bytes. Conversely, renaming an unsupported file to .bps does not make it a recognized BPS patch.
Use the Renegade Platinum’s xdelta instructions for those examples. For an unspecified package, keep the source and exact message rather than choosing a project from the filename alone.
Do not use the ordinary game patcher as a generic save converter
The Pocket Deal Radar patcher’s inputs are a base file and an IPS, UPS or BPS patch. It has no general Pokémon-save conversion workflow. Identify the save format and game version from the emulator and creator instructions, not its filename alone.
A game update and a save conversion are separate tasks. Do not select a save as the patch here. If the creator requires a save conversion, follow the instructions for those exact releases while preserving the original files.
Example: only an emulator state is available
A player wants to update an adventure and finds a recent emulator snapshot, but no verified ordinary save. Renaming the snapshot .sav will not convert it into an in-game save. Preserve the original build and state, investigate whether that setup can resume, then use the game’s own Save command if available. If it cannot, retain the original files rather than experimenting on the only progress.
For file copying after the required conversion, the save-transfer planner keeps format support and game/build compatibility as separate questions.
The base matches, but the result did not verify
Our patcher evaluates the generated output and patch checksums for UPS and BPS. If either check fails, it blocks downloading that result. A base match does not by itself establish a valid patch or output.
Start a separate attempt with the required untouched base and a fresh copy of the intended creator patch. Note the patch version and file checksums so you can compare attempts. If the same failure persists, preserve those details for the developer or patcher maintainer. Do not import your only save into an unverified output to see what happens.
Why IPS cannot give the same verification
Our IPS path has no embedded source or output checksum to compare. An unverified IPS result means no embedded checksum was available. Check any base hash supplied separately by the developer and follow the required version and patch order.
After using the intended inputs, test a fresh start before bringing in an existing save. A UPS or BPS checksum verifies the patched bytes. Test the emulator and save separately.
Three cases that can look like the same problem
Case 1: same game, same size, wrong CRC32
A file reports the expected game and revision and has the expected byte size, but its CRC32 differs from the patch’s source value. Those first two matches do not cancel the checksum difference. Recheck whether the file is an untouched input and whether the creator specifies another region or revision. Do not change emulator settings; patching has stopped before an emulator is involved.
Case 2: the main patch works, an optional patch fails
The second patch may expect a particular intermediate output. Read the maker’s required order and confirm which file you selected for stage two. Do not assume every patch in one archive is independently applied to the original base. Keep each stage identifiable; an optional patch can require a different input from the main patch.
Case 3: the output verifies, but Continue is missing
The output check has answered a patching question. Missing Continue is a save question. Confirm the game/core’s normal save file and loading procedure, keeping a backup before changing filenames or locations. Locate the existing save before trying another patch.
These are illustrative diagnostic cases, not observed failures in particular releases. The ROM-checker explanation describes the limits of header matches; the Renegade Platinum installation guide provides a separate xdelta workflow where our patcher does not apply.
Record the failed stage before retrying
A useful report identifies the creator package, patch name, tool and exact message. Add the expected source size/hash and your actual size/hash when those are shown. Say whether the input is the clean base or the result of an earlier documented stage.
- Keep the original base, intended patch and previous working game separate.
- Record the values and failure message from the current attempt.
- Change only the input that the diagnosis points to.
- Repeat the same tool workflow and compare the result.
- After success, inspect the new game and normal save behavior separately.
When a fresh creator patch and the documented input repeatedly fail, keep the record for the developer or patcher maintainer. Report the evidence rather than suppressing checksum validation or sharing a copyrighted game file.
After the patch checks pass
Open the generated game file in the appropriate emulator. Start with the GBA handheld setup guide for GBA games or the Nintendo DS guide for DS. If the game loads but progress is missing, that is a separate save problem: see the Onion save checklist when using Miyoo Mini Plus.
Keep the base, patch, output and save backups distinct. Record the exact failure point rather than changing the hack, core and firmware together.
Sources and scope
The message descriptions follow Pocket Deal Radar's current patcher implementation and verified patch-engine tests. The BPS format specification records separate source, target and patch checksums. Format reference and local implementation checked 7 Oct 2026. For runtime and save requirements, return to the game’s creator documentation.
Open the local patcher · Full patching and emulator guide · Find your game's requirements
Based on the creator's documentation, checked 7 Oct 2026. Not hands-on tested unless a section says 'We played it'.
How we check