fix

apps/sim/app/api/tools/dropbox/upload/route.ts

@@ -79,10 +79,7 @@ export async function POST(request: NextRequest) {
       fileBuffer = Buffer.from(validatedData.fileContent, 'base64')
       fileName = validatedData.fileName || 'file'
     } else {
-      return NextResponse.json(
-        { success: false, error: 'File or file content is required' },
-        { status: 400 }
-      )
+      return NextResponse.json({ success: false, error: 'File is required' }, { status: 400 })
     }
 
     // Determine final path

apps/sim/blocks/blocks/dropbox.ts

@@ -318,13 +318,13 @@ Return ONLY the timestamp string - no explanations, no quotes, no extra text.`,
         }
 
         // Normalize file input for upload operation
-        // normalizeFileInput handles JSON stringified values from advanced mode
-        if (params.file) {
-          params.file = normalizeFileInput(params.file, { single: true })
-        }
-        // Legacy: also check fileContent for backwards compatibility
-        if (params.fileContent && !params.file) {
-          params.fileContent = normalizeFileInput(params.fileContent, { single: true })
+        // Check all possible field IDs: uploadFile (basic), fileRef (advanced), fileContent (legacy)
+        const normalizedFile = normalizeFileInput(
+          params.uploadFile || params.fileRef || params.fileContent,
+          { single: true }
+        )
+        if (normalizedFile) {
+          params.file = normalizedFile
         }
 
         switch (params.operation) {