All my photos are jpg. The only immediate problem I can think is they are bigger than 15MB. https://www.familysearch.org/help/helpcenter/article/how-do-i-upload-photos-or-documents-to-memories
JPG should work. But if you have any that have extension.jpeg. Try renaming it to .jpg and see if that makes a difference (remove the letter e from the extension. See if that helps
Welcome to the "Community.FamilySearch" Forum ...
Further to what 'Dennis' has already proffered ...
Please be aware that there is a Maximum "File" Size LIMIT of 15MB.
Here is a "Knowledge Article" in 'FamilySearch':
How do I upload memories to FamilySearch?
Where it states:
For Photos, .jpg, .png, .tif, and .bmp file formats up to 15MB.
Just in case.
15MB is usually plenty of room for a photo
if anyone has images greater than 15MB - they should seriosuly consider setting their resolution settings lower on their camera. above 15MB - just makes thing painfully slow when doing file transfers or any procesing of the image - and for no good reason.