WordPress Creation Kit Pro disappears…

I’ve been developing a website, using WordPress, on and off, for a few weeks. I use the Avada Theme. All of my more knowledgeable Techy Friends warned me off WordPress from the start and most told me to use Umbraco (I’m talking top paid Web Developers, not keen amateurs like me!). I chose WordPress because I think it’s much easier to use but now I am having serious second thoughts and would appreciate any advice. 3 weeks ago I viewed my website and noticed that all the Pages that I had created using the “WordPress Creation Kit Pro” (WCK) Plugin had disappeared. I logged on to my Dashboard and sure enough the WCK Plugin had disappeared. I logged on to my server and the “wordpress-creation-kit-pro” folder was still there but it was completely empty. I do a daily backup of the website so I just recovered the contents of the folder, re-activated the WCK Plugin and hey-presto all the pages re-appeared. I was a little worried – why did this happen? Then last week, exactly the same thing happened again and once again the same fix worked. But I was even more worried. Then today, it happened again. This time the usual fix did not work because when I try to activate the WordPress Creation Kit Pro Plugin I get a fatal error – Fatal error: Cannot redeclare wck_remove_wck_submenu_page()

The Website I am developing is a Company Website and of course I cannot ever put it live while this is happening.

Has this situation ever happened to anyone here? I have read that upgrading the version of WordPress can cause such issues? If this is the case then WordPress, for me, is a non-starter.

Thanks, Ade.

(Sorry for the Essay!)