There are a few possible reasons why Photoshop cannot save as JPEG:

• Your Photoshop app is not up to date. Make sure to update your Photoshop app to the latest version.
• You are trying to save a file that is too large. JPEG files have a maximum file size of 4 GB. If your file is larger than 4 GB, you will need to save it in a different format, such as PSD or TIFF.
• You are trying to save a file that contains unsupported features. JPEG files do not support all of the features that are available in Photoshop. If your file contains unsupported features, you will need to save it in a different format, such as PSD or TIFF.
• You are trying to save a file to a read-only location. Make sure that you are trying to save your file to a location where you have permission to write.
• You have a problem with your computer’s file system. Try restarting your computer or running a disk utility program to check for errors on your hard drive.

If you have checked all of the above and you are still unable to save your file as a JPEG, you can try the following:

• Save your file as a PSD file first. Then, open the PSD file and save it as a JPEG file.
• Use a different image editing software program to save your file as a JPEG file.

If you are still having problems, you can contact Adobe support for assistance.