Through Gmail you can easily send and receive the mails and even attachment also. But yes sometime it happens when user didn’t upload the attachment. Behind this problem there are some of the reasons which you have to know.
1) Make sure if you are not able to upload any kind of attachment then might be the problem is related with your browser. Quickly check your browser by typing www.gmail.com in the address bar. If it is perfectly working then it’s ok, otherwise change the browser and choose another one. The browser which is best suitable for Gmail is: Google chrome, internet explorer, safari etc.
2) This attachment problem also occurs due to browser’s cookies and cache. So immediately clear your browser’s cookies and cache.
• Go to chrome browser and click on more icon
• Then click on more tool and select the clear browsing data.
• Then select cookies and other side data and cached images and files
• Now select the amount of data which you want to delete and click clears browsing data.
3) You can also turn off the extension
4) Disable the Gmail labs and then try to open the Gmail and upload the attachment.