How can I avoid access errors for files I upload to Blackboard?

From BbWiki

Files you are uploading from your computer to a Blackboard content area should observe the following conventions to help ensure they can be accessed and opened correctly. If you do not adhere closely to Blackboard's file naming rules, you will get errors when trying to upload documents via the digital drop box, assignment tool, and other Blackboard functions.

Filename Length

Filenames should be less than 30 characters to avoid unexpected truncations that can occur when moving between different computer platforms like Macintosh and Windows.

Filename Characters

Filenames must NOT contain unusual characters such:

\   (backslash)
/   (forward slash)
:    (colon)
;   (semi-colon)
*   (asterisk)
?   (question mark)
"   (double quotation marks)
<   (left angle bracket)
>   (right angle bracket)
|   (pipe)
%   (percent)
,   (comma)
#   (pound or number)
$   (dollar)
!   (exclamation)
+   (plus)
{   (left bracket)
}   (right bracket)
&   (ampersand)

Spaces and underscores (_) are OK.

Filename Extensions

Filenames should ALWAYS include the file type extension so that they can be recognized and opened by the appropriate application on another computer. The common extensions are:

.doc for Microsoft Word documents
.pdf for most scanned readings in portable document format (PDF)
.jpg for JPEG images such as photographs
.xls for MS Excel files
.ppt for MS Powerpoint files
.txt for plain text files

Note that these guidelines apply to the filename of the file itself. Blackboard allows you set a separate "Name of Link to File" as you are adding documents (Control Panel > Add Item) which displays as the text of the hyperlink pointing to your file. This name can be up to 255 characters and can include the symbols listed above.