[Qgis-user] problems with raster (merge, clip) and crash dumped

[Azzurra Lentini]

Hi to all,
I am using for my Bachelor classes in university  qgis 2.18 but some  
of my students have the  problems below.
They even format the computer completely and the reinstall windows 10  
+ the softwarer qgis (they even tried different versions of Qgis   
2.18) but they still have these problems (I never had these problems  
in my computers with the same versions of Qgis and with other versions).
In the new version of QGIS is better but still (in the same computers)  
  as well as is in my computer with the same versions (for example the  
merge is not perfect because the file are still separated! so I dont  
think is a problem of which version they use.

ERRORS:
When they upload files RASTER with extension  .asc they have the  
yellow message: Python error: an error has occurred while executing  
Python code

They can see well the file .asc in the project but they can not do  
MERGE  and CLIP.

MERGE
Normally they try to do the Merge of different ASC files with  
Raster/Miscellaneous/Merge and the error message is:
error 4C... no such file

Normally they try to do the clip of raster files .TIFF from  
Raster/Extraction/CLIPPER and the error message is:
"ascii" codec cant encode character u'/xe0' in position 60: ordinal  
not in range (128) ...

So I don't understand what can I do, because they have also formatted  
and cleaned the computers and in my computer and in some other  
computers everything is fine with the same versions and commands.

Another problem that is also in some other computers is that when they  
exit from the project, they have this error message (that close the  
project without saving):
CRASH DUMPED : minidump written to C ...

Thank you for any suggestion.

Azzurra