Firstly, keep in mind that those are the accepted formats:
- txt, pdf, doc, docx, xml, jpg, jpeg, png, zip, xlsx, txt, pdf, doc, docx, xml, jpg, jpeg, png, zip, xlsx.
Secondly, keep in mind that the maximal accepted size is 500 KB.
If the above requirements were checked and you are still facing the issues, please try the following:
Check if the file has zero megabytes and if positive, check the following:
- Virus, malware infection;
- Uploaded or downloaded files with unsupported attributes;
- Incomplete file uploading and downloading;
- Incomplete files received via archived emails or email attachments;
- Intentionally created 0-byte files.