Specialy that a admin cannot create invoices in frontend is very poor.
I have a small IT OnSite Support Business and when im be by a customer i want create Invoices there directly to save the nature (paper less dream ;)
But the Customer see when i create a invoice all other Customers and there invoices. :(
I moved to another webspace provider and since then when i created a pdf invoice im not able to open it (File Corrupt or damaged) The Joomla installation is absoloutly the same (with akeeba backup)
You are correct in stating that ccInvoices is a simple, user friendly invoicing extension. It is a uncomplicated system that can be used by at least 80% of businesses and individuals.
Your first point is actually a functionality request "create invoices from the frontend". Nowhere do we communicate this functionality, so it is not really relevant to review ccInvoices on that functionality.
Then, it appears you are still using ccInvoices about 3 months after you requested and received a refund. This is your right, no problem. But ccInvoices is probably not as bad as you as describing it, right?
Second, you are posting a support request to an issue which is probably not caused by ccInvoices at all. As you state, you moved the website to another server (webspace provider). Did you realize that moving the exact same website to another server still changes at least the server configuration and probably the file permissions?
In any case, the issue was easily solved by us if you would have opened a support ticket (and did not request a refund 3 months ago, but kept using ccInvoices).