Error message/code: SMTP Error: Data not accepted. Description: The "Data not accepted" error message is coming from your SMTP server. Usually when you get this message, your email shouldn't be sent, because it's being rejected by your SMTP server. Solution: Contact your host tech support...

Error message/code: TCPDF ERROR: [Image] No such file or directory in... Description: It means that article has link  to image <ing src=....> but image does not exits. Solution: Update article, remove or make link to the image correct.

Error message/code: TCPDF ERROR: Could not include font definition file: [font name] Description: By some reason TCPDF could not find required font. Solution: Install required font.