Text functions such as LEN() and RIGHT( , )ARE NOT WORKING.

When I paste a quantity of text into a cell, and then use the commands Data, Text to columns to separate the words each into separate cells, the LEN function does not report the number of letters in each word but just reports zero,
The object is to calculate the average word length in a passage of text. (part of calculating the Gunning Fog factor for readability.) This was not a problem when I made the spreadsheet in an early version of Libre Calc but since I have done some updates it now is. This might be an issue of a default that got changed but I cannot find that.

If I type a word in a cell and then in another cell use the LEN() funtion to count the letters it works fine, but not when the text to columns function fills in the words in the cells. This change has ruined my spreadsheet.

You are talking of a change. What change? From version … to version… What OS?
I rather would judge there is a problem on your system, possibly a corrupted user profile (which is capable of causing very strange behaviour of LibreOffice). There is surely not a setting to disallow the application of any functions for cells filled by ‘Text to Columns…’.
I tested a case similar to what you describe with V and it worked perfectly