diff --git a/.changes/unreleased/Fixed-20250129-095107.yaml b/.changes/unreleased/Fixed-20250129-095107.yaml
new file mode 100644
index 0000000000..9404c5fe22
--- /dev/null
+++ b/.changes/unreleased/Fixed-20250129-095107.yaml
@@ -0,0 +1,3 @@
+kind: Fixed
+body: Fix for the "Diff Edit Failed" / "replace_in_file" defects - #1010 #1511 #953
+time: 2025-01-29T09:51:07.5008655-05:00
diff --git a/src/core/Cline.ts b/src/core/Cline.ts
index c234b721b8..c9c3e3c066 100644
--- a/src/core/Cline.ts
+++ b/src/core/Cline.ts
@@ -1595,6 +1595,13 @@ export class Cline {
 									diff = fixModelHtmlEscaping(diff)
 									diff = removeInvalidChars(diff)
 								}
+
+								// open the editor if not done already.  This is to fix diff error when model provides correct search-replace text but Cline throws error
+								// because file is not open.
+								if (!this.diffViewProvider.isEditing) {
+									await this.diffViewProvider.open(relPath)
+								}
+
 								try {
 									newContent = await constructNewFileContent(
 										diff,