diff --git a/cli/conf.ts b/cli/conf.ts
index d21d9c6256..4b6f248be4 100644
--- a/cli/conf.ts
+++ b/cli/conf.ts
@@ -36,13 +36,13 @@ export async function readConfigFile(): Promise<SyncOptions> {
     ) as SyncOptions;
     if (conf?.defaultTs == undefined) {
       log.warning(
-        'No defaultTs defined in your wmill.yaml, using deno as default typescript language. Set defaultTs in wmill.yaml to "bun" to switch (https://www.windmill.dev/docs/advanced/cli/sync#wmillyaml)'
+        "No defaultTs defined in your wmill.yaml, using deno as default typescript language. Use 'wmill init' to bootstrap it."
       );
     }
     return typeof conf == "object" ? conf : ({} as SyncOptions);
   } catch (e) {
     log.warning(
-      'No wmill.yaml found, using deno as default typescript language. Create a wmill.yaml with a defaultTs set to "bun" to switch (https://www.windmill.dev/docs/advanced/cli/sync#wmillyaml)'
+      "No wmill.yaml found, using deno as default typescript language. Use 'wmill init' to bootstrap it."
     );
     return {};
   }
diff --git a/cli/sync.ts b/cli/sync.ts
index 32ffb247cf..8ec5c3541a 100644
--- a/cli/sync.ts
+++ b/cli/sync.ts
@@ -107,13 +107,13 @@ async function addCodebaseDigestIfRelevant(
   if (!isTs) {
     return content;
   }
-  log.info(`isScript: ${isScript}, isTs: ${isTs}; ${path}`);
   if (isTs) {
     const c = findCodebase(path, codebases);
     if (c) {
       const parsed: any = yamlParse(content);
       if (parsed && typeof parsed == "object") {
         parsed["codebase"] = c.digest;
+        parsed["lock"] = undefined;
         return yamlStringify(parsed, yamlOptions);
       } else {
         throw Error(
diff --git a/frontend/src/lib/components/FlowPreviewContent.svelte b/frontend/src/lib/components/FlowPreviewContent.svelte
index e64b84720e..201eb42940 100644
--- a/frontend/src/lib/components/FlowPreviewContent.svelte
+++ b/frontend/src/lib/components/FlowPreviewContent.svelte
@@ -10,7 +10,7 @@
 	import FlowProgressBar from './flows/FlowProgressBar.svelte'
 	import CapturePayload from './flows/content/CapturePayload.svelte'
 	import { AlertTriangle, ArrowRight, CornerDownLeft, Play, RefreshCw, X } from 'lucide-svelte'
-	import { emptyString } from '$lib/utils'
+	import { emptyString, sendUserToast } from '$lib/utils'
 	import DrawerContent from './common/drawer/DrawerContent.svelte'
 	import SavedInputs from './SavedInputs.svelte'
 	import { dfs } from './flows/dfs'
@@ -60,11 +60,17 @@
 		args: Record<string, any>,
 		restartedFrom: RestartedFrom | undefined
 	) {
-		lastPreviewFlow = JSON.stringify($flowStore)
-		jobProgressReset()
-		const newFlow = extractFlow(previewMode)
-		jobId = await runFlowPreview(args, newFlow, $pathStore, restartedFrom)
-		isRunning = true
+		try {
+			lastPreviewFlow = JSON.stringify($flowStore)
+			jobProgressReset()
+			const newFlow = extractFlow(previewMode)
+			jobId = await runFlowPreview(args, newFlow, $pathStore, restartedFrom)
+			isRunning = true
+		} catch (e) {
+			sendUserToast('Could not run preview', true, undefined, e.toString())
+			isRunning = false
+			jobId = undefined
+		}
 	}
 
 	function onKeyDown(event: KeyboardEvent) {