With a completely new Magento 126.96.36.199 Installation joined the error when trying to export the already created products “Invalid Entity Model” (oder auch Invalid entity model) on. This error no export was possible. Neither of products or customers.
The problem is, if the system are not enough write permissions for the temporary file available. It is generally tried this on C:\Windows Temp to create. It can happen but, that Windows refuses to allow this. You can now try the folder to miss the necessary write permissions, by right-clicking > Properties > Security einsteuert the accesses. However, this did not work for us.
However, there is another way, the work.
Just a copy of the file from the folder Abstract.php
app / code / core / Mage / ImportExport / Model / Export / Adapter
drag and copy this into the (evtl. still have to be folder)
app / code / local / Mage / ImportExport / Model / Export / Adapter
Then open the file and after line
$destination = tempnam(sys_get_temp_dir(), 'importexport_');
(as. Line 60) Search and this completely
$destination = tempnam(Mage::getBaseDir() . '/var/tmp/' , 'importexport_');
The best time to try and delete the cache. If it still does not work, then go again to the FTP client into the Magento var directory and if not yet available- Create the tmp directory (evtl. nor the write permissions e.g.. on 755 or Not 777 set).
Then, the temporary file is created in this directory, and can be downloaded as desired.
Used in Magento Version 188.8.131.52.. Ask, Comments, Suggestions? Gladly!