Dear Sir,
The problem is solved now. I am able to save the edits in texture plugin. Based on the recommendation from Alec Smecher (asmecher) to my other query (An unexpected error occurred. You may have been logged out. Please reload the page and try again - #19 by asmecher), I have asked my hosting company to allow the PUT requests for my website. They enabled it. After that, I am able to save the edits. Thanks a lot for your interactions.