You can delete the replaceable InDesign SaveData and InDesign Defaults files by holding down the following keys while InDesign is launching:
- Windows: Shift+Ctrl+Alt
- Mac OS: Shift+Control+Option+Command
Indesign CS 2021 version 16.1
Content on layer (text boxes, graphics, objects etc) are moved to box with a size of 0x0 mm that is located in the middle of spread. Contet is listed in "layer view". Moving anything from other layer make the moved ojects invisible. Trying to create anyting new on said layer freeze indesign while removing InDesing from list of running aps in Task manager (so End task is not possible)
Try resetting your preferences
If resetting preferences doesn't work - try exporting your File to an IDML
Open the IDML and resave as an indesign file.
Resetting preferences don't yeld any results.
Saving to IDML don't work as during this task ID spike up memory usage to maximum and freeze while vanishing from list of running app in task manager.
I've tried removing the content by selecting it in layer view and then exporting to XML and the content is still visibile in XML.
>> Content on layer (text boxes, graphics, objects etc) are moved to box with a size of 0x0 mm that is located in the middle of spread.
Move only this spred to new indesign document, close old, save new documetn and try again to do box not "0 mm".
clearly your document is damaged. Because exporting to IDML is not working I'd suggest the following:
 Select all items that are on that spread that is showing the non-page, that damaged page.
Do that in the Layers panel.
 Copy the selected items to the clipboard.
 Add a new spread right before that damaged spread using the Pages panel.
 Go to the new spread with both pages intact and do Paste In Place with all the items stored in the clipboard.
If you can do that successfully, save your document with a new name.
Then remove the damaged spread and save it again with Save As.
Finally, to make sure all is working well:
Export to IDML, open the IDML file as document and work on with that new document.
( ACP )