"internal error " when uploading an non-picture file

[xiaopeng xi]

in any uploading attachment scenario ( editing a task or story etc.) it is find when uploading a picture file. But when uploading any non picture file ( pdf, or zip or anything) there will an error message shown below

[xiaopeng xi]

it turns out that nginx rejected the POST request due to the oversize of the file.

[Moses Thomas]

@xiaopeng xiPlease provide what the log files says  in  {JIRA_HOME_Folder}/log/atlassian-jira.log

then show what  the logs  says  and we might be able to  help  you  accordingly.

Best!

[Nic Brough -Adaptavist-]

What does the application log file say the problem is?

[xiaopeng xi]

solved. it was my nginx limitation of POST size. 

[xiaopeng xi]

it seems to be not the problem of file type. it's the size. but I do check the max size of attachment is 10M, but when i upload over 1M this error occurs