Step 1: Right click on Measure Square 8 project (.fez), and open the file with "7-Zip File Manager". If you haven't installed "7-Zip", download it from https://www.7-zip.org/download.html.
Step 2: Open the "ImportedPlanImages" Folder.
Step 3: Click "Test" to verify which image is corrupted.
Step 5: Reopen the Measure Square 8 project (.fez file), click "Fix All Checked", and then click "OK" to recovery the file.