macOS Photos - Exporting photos and File->New Album with selection not working

We appreciate you clarifying this for us, mikevit,

How much storage do you have available on your Mac?

Are you able to set up a new user account to test exporting photos in the new user account? If so, to set up a new user account, you can go to the Apple menu  > System Preferences, then click Users & Groups.

Click the lock icon, then enter an administrator name and password.

Click the add button (+) below the list of users.

Complete the fields shown for an Administrator account, then click Create Account (or OK).

Once you’ve created the new account, go to the Apple menu  > Log Out, then log in with the new account and test. If you're able to successfully export photos in the new user account, you may have login items which may be impacting your photos. If that's the case, this article explains how to remove login items to help isolate this behavior further: Remove login items to resolve startup problems on your Mac

1. On your Mac, choose Apple menu  > System Preferences, then click Users & Groups .

2. Click your account name below Current User, then click Login Items at the top of the window.

Make a list of the login items—you’ll need to remember them later.

3. Select all of the login items, then click the Remove button .

4. Choose Apple menu > Restart.

5. If this solves the problem, open Users & Groups preferences again, add the login items one at a time, and restart your Mac after adding each one.

When the problem occurs again, follow the steps above to remove only the last login item you added.

We hope this helps.

Take care!

As a test launch Photos with the Option key held down and create a new, test library.  Import some photos and test to see if the same problem persists. Does it? This tells us if the problem is limited to your current library or is more wide spread. Then open your original library and test to see if the problem persists.

If the problem persists log into a new, basic, admin user account, Set up users, guests, and groups on Mac,  repeat the test library above and see if the problem persists. This tells us if the problem is limited to your user account or is system wide.

There could be a corrupted or damaged cache file and opening a new library clears it and starts caching anew.

Hello mikevit,

Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you're having issues with exporting photos on your Mac. Try the steps listed here to see if they resolve the issue: Export photos, videos, slideshows, and memories from Photos on Mac - Apple Support

"Export photos in a selected format

You can export photos so that you can import them and work with them in other apps. The easiest way to export photos is to drag them to a location in the Finder. You can also use the Export command, which allows you to specify file format, filename, and subfolder organization settings. You can choose the size and format for the exported photos. You can also export a Live Photo as a still image. 

1. In the Photos app  on your Mac, select the item you want to export.
2. Choose File > Export > Export [number] Photos.
3. Click the Photo Kind pop-up menu and choose the file type for the exported photos.

• JPEG creates small files suitable for use with websites and other photo apps. 
• TIFF is a lossless file format that works well for transferring photos between computers and apps.
• PNG is another lossless file format popular for web images.

1. To specify the size, quality, and other export options for a specific file type, click the down arrow beside the Photo Kind pop-menu, then select the options you want: 

• JPEG Quality pop-up menu (JPEG files only): Choose a resolution (the number of pixels in the exported image), which affects display and printing quality. 
• 16 Bit checkbox (TIFF files only): Select to export an image compatible with older 16-bit computer devices.
• Color Profile pop-up menu: Choose a color profile to maintain similar display or printing quality on monitors or printers different from your devices.
• Size pop-up menu: Choose the size of the exported image.

1. Click the File Name pop-up menu and choose how to name the exported files (this step is optional).
2. You can name your exported files using the titles you’ve given them in Photos, their filenames, or a filename numbered sequentially. If you choose Sequential, you can specify text to appear before each number (for example, Birthday - 1, Birthday - 2, and so on). 
3. Click the Subfolder Format pop-up menu and choose how to divide the exported files into folders.
4. For example, if you export photos from several different days, you can have Photos export each day as a subfolder named after the day. Choose None to export the photos as individual files without subfolders.
5. Click Export.
6. Choose where to save the exported photo files, then click Export.

Tip: If you’re signed in with your Apple ID and have iCloud Drive turned on, you can export photo files to iCloud Drive, then access them from any Mac, iPhone, iPad, or Windows PC set up to use iCloud Drive. See Use iCloud Drive to store documents.

Export photos in their original format

You can export photos in the original file format in which they were imported into your Photos library. A Live Photo is exported as two separate files: a still-image file and a video file.

1. In the Photos app  on your Mac, select the photos you want to export.
2. Choose File > Export > Export Unmodified Original.
3. If you want to export IPTC information (assigned IPTC metadata and keywords) as a sidecar XMP file, select the Export IPTC as XMP checkbox. 
4. 
5. Click the File Name pop-up menu and choose how to name the exported files (this step is optional).
6. You can name your exported files using the titles you’ve given them in Photos, their filenames, or a filename numbered sequentially. If you choose Sequential, you can specify text to appear before each number (for example, Birthday - 1, Birthday - 2, and so on). 
7. Click the Subfolder Format pop-up menu and choose how to divide the exported files into folders.
8. For example, if you export photos from several different days, you can have Photos export each day as a subfolder named after the day. Choose None to export the photos as individual files without subfolders.
9. Click Export.
10. Choose where to save the exported photo files, then click Export Originals.

Export videos

You can export videos so that you can share them or work with them in other apps. When you export a video, you can choose the movie quality and whether metadata such as a title or caption is included with the exported file.

1. In the Photos app  on your Mac, select videos you want to export.
2. Choose File > Export > Export [number] Videos.
3. Click the Movie Quality pop-up menu and choose the video format for the exported video.
4. 
5. Standard definition (480p) is good for standard-definition TV. If the video will play on a high-definition TV or display, choose one of the high-definition formats: 720p or 1080p. 4K is used for ultra-high-definition TVs and displays. 
6. Click the File Name pop-up menu and choose how to name the exported files (this step is optional).
7. You can name your exported files using the titles you’ve given them in Photos, their filenames, or a filename numbered sequentially. If you choose Sequential, you can specify text to appear before each number (for example, Birthday - 1, Birthday - 2, and so on). 
8. Click the Subfolder Format pop-up menu and choose how to divide the exported files into folders.
9. For example, if you export videos from several different days, you can have Photos export each day as a subfolder named after the day. Choose None to export the videos as individual files without subfolders.
10. Click Export.
11. Choose where to save the exported video files, then click Export.

Tip: If you’re signed in with your Apple ID and have iCloud Drive turned on, you can export video files to iCloud Drive, then access them from any Mac, iPhone, iPad, or Windows PC set up to use iCloud Drive. See Use iCloud Drive to store documents.

Export slideshows

You can export slideshows to share with others. When you export a slideshow, Photos creates a movie file with the video format that you select. 

1. In the Photos app  on your Mac, click a slideshow under Projects in the sidebar.
2. Click Export in the toolbar, or choose File > Export > Export Slideshow.
3. Enter a filename for your slideshow movie in the Save As field.
4. Click the Format pop-up menu and choose a file type for the exported movie.
5. Standard definition (480p) is good for standard-definition TV. If the slideshow will play on a high-definition TV or display, choose one of the high-definition formats: 720p or 1080p.
6. Choose where to save the exported slideshow movie, then click Save.

Export memories

You can export memories to share with others. When you export a memory, Photos creates a movie file with the video format that you select. 

1. In the Photos app  on your Mac, click Memories in the sidebar, then double-click the memory that you want to export.
2. To stop playing a memory, press the Space bar.
3. Choose File > Export > Export Memory Video.
4. Enter a filename for your memory in the Save As field.
5. Click the Where pop-up menu and choose a location for the exported memory.
6. Click the Orientation pop-up menu and choose Landscape, Portrait, or Square orientation.
7. Click the Aspect pop-up menu and choose an aspect ratio (16:9, 4:3, or Original).
8. Click Save.

Export a Live Photo as an animated GIF image

1. In the Photos app  on your Mac, select a Live Photo. 
2. Click Export in the toolbar, or choose File > Export > Export GIF.
3. Choose a location to export to, then click Export.

Export a video frame as a photo

You can review a video clip to identify an outstanding frame and export it as a photo into the Pictures folder.

1. In the Photos app  on your Mac, open a video clip, and drag the playhead to the frame you want to export.
2. Choose File > Export > Export Frame to Pictures.
3. A TIFF file named “Frame [date]” appears in the Pictures folder.

Tip: To quickly export a group of photos to the desktop, select the photos you want, then drag the selection indicator at the top right of the window to the desktop."

We hope this helps.

Cheers!