I cannot export my edited files. If I try to "save as", lightroom offers to save the picture as a *.txt file. What is going on? Is this a limitation of the trial version of lightroom that I am using?
In order to export copies of your images that include all of the Lightroom adjustments you need to use the EXPORT option that is on the menu. In the library module there is an export button in the lower left-hand corner of the interface screen. When you choose EXPORT the export dialog displays and allows you to set the number of options so that your exported images include all the features and settings that you desire. You cannot use a "save as" function in the Lightroom to save exported or edited copies of your images. You need to use the export function.