Hi, my name is Neil, and I'm an Edge user like you.
This could be cause by a few issues.
First of all, can you check to see if Edge has any available updates. To do this follow these instructions:
In Edge, click the 3 dots (...) in the upper right corner of the window.
Click on Settings.
Click on "About Microsoft Edge" on the left hand side menu.
Edge will automatically check for updates. Let any updates install and then close and re-open Edge.
Check your PDF ability to save now.
If you still have trouble, try clearing your cached history and data:
Open Edge.
Press Ctrl+H on your keyboard to open the History box.
Click the 3 dots (...) at the top of the History box.
Click on "Clear browsing data”.
In the drop-down "Time range" box select "All time".
Make sure the first 4 boxes are checked (Browsing history, Download history, Cookies and other site data, and Cached images and files).
Click the "Clear now" button.
Let Edge clear the data.
Afterwards, close Edge.
Then re-open Edge.
Check your PDF ability to save now.
If you still have trouble, is this happening to all PDF documents or just this one? Is the document stored locally on your computer or is it stored online?
If this is happening to all PDF's, try resetting Edge:
Open Edge
Click on the three dots (…) in the upper right corner of the window.
Select Settings from the drop down and click on "Reset settings" from the left hand side menu.
Click on "Restore settings to their default values".
Click the "Reset" button.
Relaunch Edge and check your PDF ability to save now.
****Please note****: This will reset your startup page, new tab page, search engine, and pinned tabs. It will also disable all extensions and clear temporary data like cookies. You favourites, history and saved passwords will not be cleared.
Let me know how you get on.
kindest regards,.
Neil