Permissions issue I reckon

By default generally TKL apps are configured to have the tightest security possible. This usually means that root owns most of the directory tree, with the webserver user (www-data) given read access to the doc root and write access only to the specific files/folders that it needs (often a cache folder among others...)

Going from the error message you have posted I am guessing that this is your problem. From there you have the option of giving the webserver ownership of the whole directory tree. It shouldn't be a major security risk, although you'll need to be a little more vigilant with making sure you apply any security updates to the app. From experience with TKL I suspect that SugarCRM is installed to a sub-directory of the default webserver doc root. Assuming that's the case do it like this:

chown -R www-data:www-data /var/www/sugarcrm

Or you could try giving it ownership of just the root folder (that should allow the webserver to create new files/folders, but not change any files). If the file already exists then state the file, rather than the folder. This way you can easily return permissions to default when you are finished.

chown www-data:www-data /var/www/sugarcrm

or for a file:

chown www-data:www-data /var/www/sugarcrm/filename

To change back, rerun the commands but change www-data for root.