Hello,

I get the following error, with the Button "Invoice PDF":

--> "TCPDF ERROR: Some data has already been output, can't send PDF file"

The strange thing is that with the Button "E-Mail" the PDF is correctly generated and send.

Any ideas what I can do?

Hello,
please, refer to previous posts on these forums, this has been already discussed here.

i have the same problem and other threads do not solve it, please help

Hello,
I hope the problem is solved now. Users with the same issue should try upgrading to the latest version first.

In general, the most often reason for the problem may be some forgotten chars in source codes, either before opening <?php tag or after the closing one ?>. Some text editors may cause this, so be careful when editing the source files.