I have imported photos into lightroom that were stored on an external hard drive. I worked through this with an adobe technician. When I closed the program and reopened on a different day, lightroom has no photos stored. All 800 photos are not shown. Please walk me through retrieving these photos and manipulating them in lightroom and storing them on an external drive. I have called tech support for adobe and was put on hold for 3 hours.
First, make sure the external hard drive is attached and turned on.
Inside LR, make sure you have opened the correct catalog. Sounds like you may have created a new and empty catalog.
See the menu:/file/open-recent