Pages blacked out on the screen

Just updated to latest version of LO for Mac Also loaded newest version of Java. Loaded my book file (almost 300 pages). As I move around in the file, areas or pages are blacked out on the screen.

Please upload a sample which shows this issue.

I cannot imagine how to upload a sample. Please guide me on that. I have written the text of the book and I am Formatting pages/paragraphs. As I move through the open document some page or pages suddenly goes black. I continue scrolling past the blacked out area, then scroll back to see the page.

Also, as I move the mouse around a page(s), it is leaving little marks along the path across the document. These do not print, and usually go away quickly. Maybe I should just reinstall the latest version. I will try to make a different document just to see if this behavior appears on the new doc as well.

I made a new document, less than one page long. The marks left by the cursor moving across the page do appear. I did not see any blacking out as described with the much large document.
In the next 24 hours I will try reinstalling the latest version of Libre Office for Mac and report back whatever changes or does not change.

Screen Shot 2018-08-18 at 6.13.17 PM Screen Shot 2018-08-18 at 6.22.49 PMScreen Shot 2018-08-18 at 6.23.34 PM These are examples of the blackouts I have been observing in LO Writer. My computer is a Mac with OS 10.13.6, 2.5 GHz intel core i5, 8 GB 1333 MHz DDR3, The document is a 300 page book. This behavior (see screenshots) began after I started formatting with Writer. I’m scared that the file is corrupted or too big for the available memory.