I copied the following post from the Version 4.x Bug Report section because I'm seeing the same thing in v5.5.4216 R2, even though it says it was fixed in 4.01:

persona wrote: I am using Kentico version 4.0 and constantly keep getting this error saying that a transformation does not exist -

[CMSDataProperties.LoadTransformation]: The file '/CMSTransformations/Ecommerce/Transformations/Product_Preview_BD.ascx' does not exist.

Surprisingly, if I refresh the page, it loads the transformation and the page works fine. I have tried to save all virtual objects to the file system in CMS Site Manager -> Administration -> System -> Deployment interface by clicking the button “Save all virtual objects to disk”. Also restarted the application after that. But it did not help. It still shows the same error.

Has anyone else experienced this problem? Is there any solution to this? I have never noticed anything like this in earlier versions?

Note that I haven't done the "Save all virtual objects to disk" step because I'm wary of the warning: "Please note that you may need to manually delete some files if you changed the object code names or deleted the objects between two deployments" and I have no current need to pre-compile or to run the site in a Medium Trust environment.

Surely the site should work properly without this extra step? As stated in the original post, once I refresh the page I don't get that error. It only seems to occur if I visit the site after it hasn't been visited for a long time.

Thanks.