PrestaShop module TECHNICAL ERROR

On a PrestaShop 1.3.2.3 installation I purchased the One Page Checkout 1.2.2 and installed it. After that I got the following error message when trying to add a product to the basket in the shop front end: TECHNICAL ERROR: unable to add the product.

Details:
Error thrown: [object XMLHttpRequest]
Text status: parserror

Solution: The reason is the web server is running in SAFE MODE and the user owning all the PrestaShop files is the FTP user I use to upload the shop. When installing the One Page Checkout module it will be owned by the user running the web server process (in my case www-data:www-data). In SAFE MODE a php script is not allowed to execute a script owned by another user. The solution is to set the owner of all the order-files in the PrestaShop directory to my FTP-user (including the files installed by the OPC module). In a shell this is simply done by the chmod command: cd prestashop-installation-dir chown -R my-user:my-group order* (Replace prestashop-installation-dir with the real path where PrestaShop is installed and my-user:my-group to the userid:grouid owning the rest of the files in the Prestashop installation.)

Prestashop 1.2.x not showing Categories box

Problem: In the front system (FS) Prestashop is not showing the Categories box. In the back system (BS), clicking on the Catalog tab shows just a blank page, or an error message saying the page is unavailible. The probable reason is that your Home category is missing or messed up. The problem is that you can’t get into the Catalog tab in the backend system to fix it. I ended up in this situation by trying to import categories as a CSV (comma/semi colon separated file) and I had a category in that file with ID = 1. Category ID number 1 is reserved for the Home category. Prestashop did not filter this or issue a warning during the import. So take it from me – do not try to import a category with ID = 1. Prestashop table ps_category in phpmyadminSolution: I opened my database with phpmyadmin and went to the ps_category table. The row for id_category 1 was messed up and by comparing it to a backup I set it to: id_category = 1, id_parent = 0, level_depth = 0, active = 1. The dates I left as they were. Then I went into the table ps_category_lang and made sure that there were entries for id_category 1 for all languages that I had installed (I had two in my system). Voila, back and front system now works. By adjusting the ID:s in my category import file (making sure no ID was 1) it worked like a charm to import it.