diff --git a/src/core/Cline.ts b/src/core/Cline.ts
index c1c5bf186a..7a118d10a8 100644
--- a/src/core/Cline.ts
+++ b/src/core/Cline.ts
@@ -1602,6 +1602,13 @@ 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,