Before I can answer, would you mind giving me some additional details about your situation?
What mobile device are you using?
What Operating System?
Which SmartOffice version (current version is 2.3.10)
Where are the problem documents stored (on your device or on Dropbox or Box)?
What type of document is are you trying to print (Word, Powerpoint, Excel or PDF)?
What size paper are you using?
Does this problem happen with all files or some files?
Do you use spaces or special characters in your file names?
This information will be help me diagnose the problem.