List View Threshold Limit Effects

If SharePoint List view exceed threshold limits, It will block the below operations

Blocked operations when list exceeds the List View Threshold

Add/Remove/Update a list column	All columns including lookup and calculated columns, in addition to many types of updates, such as a type change or a uniqueness change. Some updates, such as a name change, are not blocked because they do not affect every item in the list.
Add/Remove/Update a List Content Type	Affects every item in the list so it is blocked for any list that has more items than the list view threshold.
Create/Remove an Index	Affects every item in the list so it is blocked for any list that has more items than the list view threshold.
Manage files which have no checked in version	A non-indexed recursive query that fails for any list that has more items than the list view threshold.
Non-indexed recursive queries	Includes filters and some sorts. This operation fails when the list size is greater than the list view threshold. Because there is no index, it does a full scan against the entire list. Also it returns all items, and it ignores folders.
Cross list query	Includes queries by the content query Web Part and follows the list view threshold setting for auditors and administrators, which by default is 20,000. If the operation involves more than 20,000 items, the query fails.
Lookup columns that enforce relationship behavior	You cannot create lookup columns that enforce relationship behavior when the list it references contains more items than the list view threshold.
Deleting a list	Affects every item in the list so it is blocked for any list that has more items than the list view threshold.
Deleting a site	If the sum of all items in a site is greater than the list view threshold, deleting the site is prevented because it affects too many items.
Save List as Template with Data	Affects every item in the list so it is blocked for any list that has more items than the list view threshold.
Showing Totals in List Views	Performs a query against every item in the list so it is blocked for any list that has more items than the list view threshold.
Enable/disable attachments in a list	Affects every item in the list so it is blocked for any list that has more items than the list view threshold.

Blocked operations when container exceeds the List View Threshold

Delete/Copy/Rename a folder	Fails when the folder contains more items than the list view threshold because it affects too many rows.
Queries that filter on non-indexed columns	Fails when the container (folder or list) contains more items than the list the view threshold because it does a full scan against the entire folder because there is no index.
Set fine grained security permissions	Fails whenever the list or folder on which you are trying to set fine grained permissions contains more items than the list view threshold because it affects too many rows. You can still set fine-grained permissions on child items, such as documents, in a large list, although you cannot set the permissions on the list itself or on folders that contain more items than the list view threshold.
Open with Explorer	Does not show any items if a container has more items than the list view threshold (excluding items in sub folders). If a folder has 8,000 items total, but it has a sub folder that contains 4,000 items and only 4,000 items in the root, then Open with Explorer will work. If the root of a list contains more items than the list view threshold then Open with Explorer will not show anything. To use Open with Explorer the list must have items organized into folders in amounts less than the list view threshold in the root of any container.