diff --git a/Installation-Guide.md b/Installation-Guide.md
index 883737e..066dfd3 100644
--- a/Installation-Guide.md
+++ b/Installation-Guide.md
@@ -570,6 +570,10 @@ If using HTTPS make sure it's properly configured: https://github.com/freescout-
 
 The only solution is to disable Rocket Loader in CloudFlare (see [this](https://github.com/freescout-helpdesk/freescout/issues/3452)).
 
+### — ERROR: Path cannot be empty at FilesystemAdapter.php
+
+This means that PHP can not create a temporary file. On Windows for example you need to give PHP permission in IIS 10 to write to `C:\Windows\temp\`.
+
 ### — Sometimes authenticated user unexpectedly logs in under another user
 
 If you are using NGINX Proxy Manager or any other proxy, disable all kinds of Assets Cache (like in [this issue](https://github.com/freescout-helpdesk/freescout/issues/3837#issuecomment-1971856397)).