Calc won't display spreadsheets, Ubuntu 20.04

When i open or create a spreadsheet in calc, the screen winks and nothing appears to happen. If I right click on the calc icon and select “all windows” a two tone box with the letter “x” in each half appears. (I’ll try to include a screen shot). How do I fix this and get back to my spreadsheets? image description

Ubuntu 20.04 LTS;
Libre Office Version: 6.4.6.2
Build ID: 1:6.4.6-0ubuntu0.20.04.1

No real steps, I did fiddle with settings on some open spreadsheets to try to get rid of sidebar in hopes of being able to resize and suddenly I got the weird box instead of my spreadsheets.

Edit your question title so that it makes sense when seen in the question list. A title should be a summary of the problem in less than 10 words.

Elaborate the symptoms in the description. The description can be as long as you deem fit. Separate each paragraph with double Returns (otherwise they are composed as a single giant paragraph.

Don’t forget minimal technical data: OS name and LO version. Give all steps necessary to try and reproduce the issue.

I wrote edit above because this is a Question & Answer site, not a forum. Here answers are reserved for solutions.

You have a duplicate at 269001/suddenly-when-i-open-a-spreadsheet-or-try-to-create-one-using. Delete it to avoid confusing contributors who won’t know to which occurrence to answer.

Your manipulations may have reduced the window to a ridiculous small rectangle leaving no room for any content. Since the last window size is retained, Calc reopens with this unusable size.

Try to hover your mouse on the window border. When the cursor changes to a double-ended arrow, press the (left) mouse button and drag to enlarge the window. Picking an angle allows to operate on the x- and y-axis simultaneously.

Alternatively, double-click on the window top frame but, caution! avoid clicking too close the red circle with “x” or you’ll terminate Calc. When the window is full screen, use your mouse to reduce to an acceptable size.

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Thank you, that worked.