everytime I try and open eM Client having had to uninstall due to error message all I get is error messages asking me to contact eM Client 
Hello, this appears to be a sign of database corruption. Unfortunately in this case, there is nothing left to do but to delete all of your data, your entire database, and start over with a blank one. To delete your database, enter %appdata% in the address bar of a file explorer and delete the “eM Client” folder. After that, launch eM Client and you can start using it.