There are many reason that your data might not be visible, but let's start with the most common reasons:
Refresh your data
IGB allows you to open files from your desktop, local servers, URLs or other data sources. This can be done through File>Open, or by simply dragging and dropping the file of choice. However, IGB do NOT instantly open these files. Often times, files are very large, there is a long list of the files you would like to see or internet service can be laggy. After adding files to IGB, they can be seen in the Chose load mode list in the center of the Data Access panel. At this point you must refresh to see the data. You can set the individual files to load only the Region in View (zoom in to a specific region or gene) or you can set it to Whole Chromosome which will load the entire sequence, be it a chromosome, or a contig, etc. You can then either refresh one file/track at a time using the symbol next to the track name or you can load everything at once by using the Refresh Data button. For more about loading files, please see