XF 1.4 plugin install error

[ŽivaAkcija]

when try install any plugin got this error Please enter a valid file name. The requested file could not be read.

all files are uplaoded in the root?

 

[ŽivaAkcija]

now in forum when try to change simple avatar got this message The uploaded file is too large for the server to process.

 

[Mike]

Something has changed with your server's PHP upload configuration. I would recommend you contact your host about it.

 

[ŽivaAkcija]

also something changes value for data and internal_data to 775?