diff --git a/apps/sim/blocks/blocks/discord.ts b/apps/sim/blocks/blocks/discord.ts
index 94c27d448..79331eaac 100644
--- a/apps/sim/blocks/blocks/discord.ts
+++ b/apps/sim/blocks/blocks/discord.ts
@@ -1,6 +1,7 @@
 import { DiscordIcon } from '@/components/icons'
 import type { BlockConfig } from '@/blocks/types'
 import { AuthMode } from '@/blocks/types'
+import { normalizeFileInput } from '@/blocks/utils'
 import type { DiscordResponse } from '@/tools/discord/types'
 
 export const DiscordBlock: BlockConfig<DiscordResponse> = {
@@ -579,17 +580,11 @@ export const DiscordBlock: BlockConfig<DiscordResponse> = {
 
         switch (params.operation) {
           case 'discord_send_message': {
-            const fileParam = params.attachmentFiles || params.files
-            const normalizedFiles = fileParam
-              ? Array.isArray(fileParam)
-                ? fileParam
-                : [fileParam]
-              : undefined
             return {
               ...commonParams,
               channelId: params.channelId,
               content: params.content,
-              files: normalizedFiles,
+              files: normalizeFileInput(params.attachmentFiles || params.files),
             }
           }
           case 'discord_get_messages':
diff --git a/apps/sim/blocks/blocks/jira.ts b/apps/sim/blocks/blocks/jira.ts
index c2e64ce1e..3d67b3902 100644
--- a/apps/sim/blocks/blocks/jira.ts
+++ b/apps/sim/blocks/blocks/jira.ts
@@ -1,6 +1,7 @@
 import { JiraIcon } from '@/components/icons'
 import type { BlockConfig } from '@/blocks/types'
 import { AuthMode } from '@/blocks/types'
+import { normalizeFileInput } from '@/blocks/utils'
 import type { JiraResponse } from '@/tools/jira/types'
 import { getTrigger } from '@/triggers'
 
@@ -869,11 +870,10 @@ Return ONLY the comment text - no explanations.`,
             if (!effectiveIssueKey) {
               throw new Error('Issue Key is required to add attachments.')
             }
-            const fileParam = params.attachmentFiles || params.files
-            if (!fileParam || (Array.isArray(fileParam) && fileParam.length === 0)) {
+            const normalizedFiles = normalizeFileInput(params.attachmentFiles || params.files)
+            if (!normalizedFiles || normalizedFiles.length === 0) {
               throw new Error('At least one attachment file is required.')
             }
-            const normalizedFiles = Array.isArray(fileParam) ? fileParam : [fileParam]
             return {
               ...baseParams,
               issueKey: effectiveIssueKey,
diff --git a/apps/sim/blocks/blocks/microsoft_teams.ts b/apps/sim/blocks/blocks/microsoft_teams.ts
index 04cb2d242..44324e426 100644
--- a/apps/sim/blocks/blocks/microsoft_teams.ts
+++ b/apps/sim/blocks/blocks/microsoft_teams.ts
@@ -1,6 +1,7 @@
 import { MicrosoftTeamsIcon } from '@/components/icons'
 import type { BlockConfig } from '@/blocks/types'
 import { AuthMode } from '@/blocks/types'
+import { normalizeFileInput } from '@/blocks/utils'
 import type { MicrosoftTeamsResponse } from '@/tools/microsoft_teams/types'
 import { getTrigger } from '@/triggers'
 
@@ -344,10 +345,9 @@ export const MicrosoftTeamsBlock: BlockConfig<MicrosoftTeamsResponse> = {
         }
 
         // Add files if provided
-        const fileParam = attachmentFiles || files
-        if (fileParam && (operation === 'write_chat' || operation === 'write_channel')) {
-          const normalizedFiles = Array.isArray(fileParam) ? fileParam : [fileParam]
-          if (normalizedFiles.length > 0) {
+        if (operation === 'write_chat' || operation === 'write_channel') {
+          const normalizedFiles = normalizeFileInput(attachmentFiles || files)
+          if (normalizedFiles) {
             baseParams.files = normalizedFiles
           }
         }
diff --git a/apps/sim/blocks/blocks/slack.ts b/apps/sim/blocks/blocks/slack.ts
index 0ce640032..68e0a7a27 100644
--- a/apps/sim/blocks/blocks/slack.ts
+++ b/apps/sim/blocks/blocks/slack.ts
@@ -1,6 +1,7 @@
 import { SlackIcon } from '@/components/icons'
 import type { BlockConfig } from '@/blocks/types'
 import { AuthMode } from '@/blocks/types'
+import { normalizeFileInput } from '@/blocks/utils'
 import type { SlackResponse } from '@/tools/slack/types'
 import { getTrigger } from '@/triggers'
 
@@ -620,12 +621,9 @@ Return ONLY the timestamp string - no explanations, no quotes, no extra text.`,
             if (threadTs) {
               baseParams.thread_ts = threadTs
             }
-            const fileParam = attachmentFiles || files
-            if (fileParam) {
-              const normalizedFiles = Array.isArray(fileParam) ? fileParam : [fileParam]
-              if (normalizedFiles.length > 0) {
-                baseParams.files = normalizedFiles
-              }
+            const normalizedFiles = normalizeFileInput(attachmentFiles || files)
+            if (normalizedFiles) {
+              baseParams.files = normalizedFiles
             }
             break
           }
diff --git a/apps/sim/blocks/blocks/telegram.ts b/apps/sim/blocks/blocks/telegram.ts
index 65b18677a..8cdb9ae72 100644
--- a/apps/sim/blocks/blocks/telegram.ts
+++ b/apps/sim/blocks/blocks/telegram.ts
@@ -1,6 +1,7 @@
 import { TelegramIcon } from '@/components/icons'
 import type { BlockConfig } from '@/blocks/types'
 import { AuthMode } from '@/blocks/types'
+import { normalizeFileInput } from '@/blocks/utils'
 import type { TelegramResponse } from '@/tools/telegram/types'
 import { getTrigger } from '@/triggers'
 
@@ -312,16 +313,9 @@ export const TelegramBlock: BlockConfig<TelegramResponse> = {
             }
           }
           case 'telegram_send_document': {
-            // Handle file upload
-            const fileParam = params.attachmentFiles || params.files
-            const normalizedFiles = fileParam
-              ? Array.isArray(fileParam)
-                ? fileParam
-                : [fileParam]
-              : undefined
             return {
               ...commonParams,
-              files: normalizedFiles,
+              files: normalizeFileInput(params.attachmentFiles || params.files),
               caption: params.caption,
             }
           }
diff --git a/apps/sim/blocks/utils.ts b/apps/sim/blocks/utils.ts
index 52ddbf3b9..cb7d5b418 100644
--- a/apps/sim/blocks/utils.ts
+++ b/apps/sim/blocks/utils.ts
@@ -249,3 +249,37 @@ export function createVersionedToolSelector<TParams extends Record<string, any>>
     }
   }
 }
+
+/**
+ * Normalizes file input from block params.
+ * Handles the case where template resolution JSON.stringify's arrays/objects
+ * when they're placed in short-input fields (advanced mode).
+ *
+ * @param fileParam - The file parameter which could be:
+ *   - undefined/null (no files)
+ *   - An array of file objects (basic mode or properly resolved)
+ *   - A single file object
+ *   - A JSON string of file(s) (from advanced mode template resolution)
+ * @returns Normalized array of file objects, or undefined if no files
+ */
+export function normalizeFileInput(fileParam: unknown): object[] | undefined {
+  if (!fileParam) return undefined
+
+  if (typeof fileParam === 'string') {
+    try {
+      fileParam = JSON.parse(fileParam)
+    } catch {
+      return undefined
+    }
+  }
+
+  if (Array.isArray(fileParam)) {
+    return fileParam.length > 0 ? fileParam : undefined
+  }
+
+  if (typeof fileParam === 'object' && fileParam !== null) {
+    return [fileParam]
+  }
+
+  return undefined
+}