Hi Srini --
I think you have two questions here. With the issue regarding the font, I did a quick google search and found a few (other) forum threads where people are reporting the same issue. This one, seems to have a solution. I know it is for centos, but you -should be able to install an RPM in ubuntu as well.
For your OTHER question, the one referred to in the subject, I did come across something like this recently, though it was for an older version of Liferay -- 6.2 in fact. Couple of questions for you --
1. Are any of the files generating previews? for example, JPGs are fine, but PDFs never seem to work
2. Are you working in a clustered environment? ... I have seen cases where the preview shows up on one server, but not the other and it is related to the environment configuration (eg. each node configured with a different document store)
3. On the subject of document store - can you share with us which Document storage type you have configured?
There are also a whole pile of properties that are associated with the preview generation. Some of them are just to control the output of course, but others are used to toggle it on and off -- and there are dependencies on other properties as well. Here are the default values, but I would suggest using the control panel to see what values are in place in your runtime
#
# Set the maximum file size for preview and thumbnail generation. Files
# larger than the value specified in this property will not result in the
# execution of a processor that generates a preview. A value of -1 indicates
# that all files will be processed. A value of 0 indicates that no files
# will be processed. The default maximum size is 100 megabytes.
#
dl.file.entry.previewable.processor.max.size=104857600
#
# Set the values related to preview and thumbnail generation for document
# library files. The classes enabled under "dl.file.entry.processors" will
# utilize these parameters to generate the necessary files.
#
# Some parameters are applied universally across all processors (e.g.,
# dl.file.entry.thumbnail.max.height) while others are specific to certain
# types of generation, as specified (e.g.,
# dl.file.entry.preview.document.depth).
#
# If the property "dl.file.entry.preview.video.height" or the property
# "dl.file.entry.preview.video.width" is set to 0, then respective height
# and width of the video file will be used.
#
# See the properties "imagemagick.enabled", "openoffice.server.enabled", and
# "xuggler.enabled".
#
dl.file.entry.preview.enabled=true
dl.file.entry.preview.document.depth=8
dl.file.entry.preview.document.dpi=300
dl.file.entry.preview.document.max.height=0
dl.file.entry.preview.document.max.width=1000
dl.file.entry.preview.video.height=360
dl.file.entry.preview.video.width=640
Lastly, though I am not sure it would help, there is a 7.0 GA6 -- have you tried possibly upgrading to the latest version to see if there is a fix that solves your problem?
