Greetings! :)
The problem is:
The file cannot be previewed in your web browser. Please try to download the file and open it locally. You can also try to install a plug-in that can open the file in your web browser.

Just some days ago I was enable to open these files, but now it doesn't work

Help me out O.o

Yours Jepposk

What file type is it? Please note a lot of file types cannot be open in a web browser. If you have installed plug-ins, then you can open PDF, Flash, MP3, MIDI, WORD / PPT, MOV, and WMV / WMA / Real Media files, etc.

If it cannot be open online in a browser, you can still download it to local and open it locally.

 

plug-in

 My file is a .stp file.  I click download and it won't download and it won't open in my browser.