Don't sync some files via desktop client

Hi all!
I don’t understand why I have the problem with sync some files. For example I have the file (3.4 MB) and try to sync via desktop client and I have the error: “Server replied: request entity too large” (upload_max_filesize 14.6G, post_max_size 14.6G), but if I rename an extension of file to another (DTP.1), I can upload file to my folder on the server. The same problem with well-known extensions .rar, .png etc. But at the same time the other zip, rar, jpg, png etc files uploaded without problem.

P.S. I tried to upload this file via browser and I don’t receive any response and don’t have the file on the server.

Do you have ideas how to solve an issue?

Found a solution