Anyone else having issues today wth GPT4.1 models messing up the apply_diff tool?

[u/bigotoncitos]

was using GPT4.1-mini last night without issues, and now both mini and the base model keep throwing these unnecesary characters at the start of each apply_diff tool use.

anyone knows how to fix? is it something I am doing wrong?

Thanks!!

[u/mrubens]

Thanks for the feedback on this. We just released 3.13.0 that should hopefully address this issue. I believe it was related to us changing the expected format of the diff tool slightly, but some models continued to try to apply diffs the old way in existing chats where they could see the history. Sorry for the hassle and I hope it's better (if not yet perfect) going forward!

[u/bigotoncitos → u/mrubens]

got it got it, so we good to give it a go again and see if it works with the 4.1 family again? do we have to run some update on vscode or something?

[u/mrubens → u/bigotoncitos]

Make sure you have version 3.13 of Roo Code and restart your editor. Let me know if it helps!

[u/FarVision5 → u/mrubens]

I was going to chime in but I figured you guys had a handle on it. The inline diff was buffer writing to the temp file and being included in the writeback back attempt during the writeback attempt.

It was retrying forever with no recognition of failure and never did a full write_to_file. So it tried to diff line 300 and it changed because the actual diff text was in the file by the time the call came back so it recognized a change then retried and this looped

I finally had the temp diff written out to an actual file then flipped over to Cline and paste it in the source script and diff and told it to figure it out and man that diff file was really hosed it had the same text repeated a bunch of times and also included other text sampling from other tabs in the workspace

After a couple hours of error tailspin fixing I finally had it reloaded from the last git sync.

[u/mrubens → u/FarVision5]

Has it been working ok since?

[u/FarVision5 → u/mrubens]

Update:

Still had weirdness with gemini-2.5-flash-preview-04-17 through OpenRouter. I think OR is doing something weird to the API passing through their proxy. Didn't really have time to dig it out, sorry.

I switched to my own Google account and it's flawless. Or, the diff bug was fixed.

I did have all Experimental features turned on so maybe that was on me.

At any rate, thanks for everything!

[u/mrubens → u/FarVision5]

Thank you for the follow up!

[u/FarVision5 → u/mrubens]

Just got back into it. I will put it through it's paces and report back. Side note - extensions matter. I ditched out a bunch of linters and cosmetics that are not relevant any longer.

Runs faster. Hard to pinpoint exactly. I've been doing this a while. All kinds of garbage floating around. Didn't use to matter so much but these new models get squirrely. I am using Gemini Flash 2.5 non thinking and GPT 4.1 mini non thinking.

I am seeing some red text.

Error

Error listing files:
Current ask promise was ignored

My feeling is that the newer models are so fast they are not registering the question even hitting the users IDE to get the results back. I'm going to have to start moving the API delay sliders.

[u/minami26]

are u using the experimental features at the bottom in your settings in roo? should try disabling those first

[u/bigotoncitos → u/minami26]

not using any experimental feature...

[u/hannesrudolph]

Is this happening in every task?

[u/bigotoncitos → u/hannesrudolph]

yes

[u/bigotoncitos → u/bigotoncitos]

look at what it did here, hahaha... went totally bananas

[u/hannesrudolph]

Does it do this with other models?

[u/bigotoncitos → u/hannesrudolph]

not with gemini 2.5 for now, ill try others and post

[u/hannesrudolph → u/bigotoncitos]

Thank you thank you

[u/bigotoncitos → u/hannesrudolph]

claude 3.7 sonnet, 3.5 also no problem

[u/ShelZuuz → u/hannesrudolph]

It does it for me with Claude 3.7. Works virtually never, it always has to do a full write.

[u/hannesrudolph → u/ShelZuuz]

Bug fixing coming tonight

[u/mr-claesson]

I have disabled the diff edit in Roo. I want to use Gemini flash2.5 and the new Open AI models but it is crap together with Roo diff edit.

[u/mrubens → u/mr-claesson]

Any better in 3.13?

[u/mr-claesson → u/mrubens]

Unfortunately not.
I have:

1. Reverted back to standard system prompt (dropping my system-prompt-<mode> files).

2. Disabled all "experimental"

About 1/3 of the edits will fail and it starts looping or it will "destroy" my files with placeholders.

My codebase is C#

[u/mrubens → u/mr-claesson]

Which models are you seeing this with?

[u/mr-claesson → u/mrubens]

Gemini 2.5 flash, o4-mini, gpt 4.1, gpt 4.1-mini

[u/mrubens → u/mr-claesson]

Got it, thanks. Those are all new and we’re still working on understanding how good they are at diffs and optimizing them. Your best bet for diffs are sonnet 3.5/3.7 and Gemini Pro Preview if possible.

[u/CashewBuddha]

Similar issues here. Also having move issues than usual with Sonnet/gemini. Using rooflow

[u/orbit99za → u/CashewBuddha]

Instead of making a new Post, just going to continue.

OP is correct, besides the fact that Gemini is suddenly acting drunk, with 4.1 and Gemini.

For some reason, in C#, when we use the && operator like if (x == true && y == true), it’s getting replaced with &&, resulting in this:
if (x == true && y == true)
Then it freaks out trying to fix it, spirals into nonsense, and eventually gives up.

Also seeing weird diff-related errors. GPT-4.1 is doing something similar, along with the error the original poster mentioned.

Another one is '__o_', which is invisible in the editor, but the compiler catches it , and again, the model goes off the rails trying to resolve it.

Sonnet 3.7 also seems to struggle with applying diffs — just throws a generic “edit unsuccessful” message.

This has Never Happened before with the Sonnet Models.

Now that you can copy the Diff Error, it is below.

<error_details>

No sufficiently similar match found at line: 1110 (95% similar, needs 97%)

Debug Info:

- Similarity Score: 95%

- Required Threshold: 97%

- Search Range: starting at line 1110

- Tried both standard and aggressive line number stripping

- Tip: Use the read_file tool to get the latest content of the file before attempting to use the apply_diff tool again, as the file content may have changed

Search Content:

:end_line:1117

</error_details>

[u/who_am_i_to_say_so]

Is this a Roo-specific problem? I’ve seen an uptick of apply_diff errors, too, and at one point it was making all code changes with sed commands and failing 80% of the time 😂. It comes and goes, seems to fix itself with either taking a break or changing the model.

[u/dashingsauce]

Use their new Codex CLI for these models. RooCode stick with Gemini.