Windows update KB5005565 breaks Adobe Reader on some computers. You can check your Windows updates to see if any pending updates, if you see it, install it and it may fix your Adobe reader issue. If that does not, try the following options.
Some computers show Save as blank
Option 1: Repair Adobe Reader
Open Apps & features and select Adobe Reader, then choose Change>Repair installation … Then click Next to start the repair process.
Tip: you can open Programs and Features older style by Start>Run>type appwiz.cpl then hit Enter
Option 2: Unselecting online save option
Open Adobe Reader, then go to Edit>Preferences… or press Ctrl+K
Uncheck both of these options: if you are not using online storage for saving or sharing Show online storage when opening files Show online storage when saving files
You can find some more info on the Adobe community:
Adobe Reader is used everywhere these days, many browsers supported built-in PDF viewer. Since Adobe Acrobat Reader came out, many features are added for the paid version, but if you are using just free Reader, this Tool pane is just annoying. Every time you open the PDF document in Adobe Acrobat Reader. You have three options To hide Tools Pane or To Remove Tools Pane or Other options. If you are not using any paid version of Adobe application removing is best option by editing Adobe Acrobat installation file. This option will Remove Tools pane, will not be able to open, which is best if you are not using any paid version cloud-based application.
To hide the Tool Pane:
Open Adobe Acrobat Reader or any PDF document Document
Click on the Arrows to hide the Tool Pane
Or you can click on View>Show/Hide>Tools Pane
or use keyboard and press Shift+F4
Once you have hiden the Tools Panes, then Go to Edit>Preferences Select Documents under Categories, then on right side select checkbox “Remember the current state of Tools Pane“
Open a any PDF document and the Tools Pane should be hidden, and can be shown with the Shift+F4 key as before.
Remove Tools pane
To remove it, you will need to open installation of your Adobe Acrobat Reader and edit Viewer.aapp file by right click on the file and open in notepad or any text editor, my file location is: C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\AcroApp\ENU\Viewer.aapp
Then comment out or delete this code from the file
Open any PDF document and the Tools Pane should be removed if you need to put it back in future you will need edit this file or re-install Adobe Acrobat Reader.
This option is for advance users and requires you to make changes to registry key, which can cause issue, if not done correctly. For Acrobat DC your registry path might be slightly different, please look for the similar or same name. Make sure to close Acrobat Reader if it is opened