NAV 2018 Extension_Error

Hi All,

        I have created one Extension in NAV 2018,installed properly worked but when I uninstalled this extension from Extension Management page and again installed then it show that error...

"Could not upgrade the NAV extension 'FirstExtension' due to the following error: 'The following tables contain data but cannot be upgraded because the relevant upgrade instructions are missing"

      if anyone knows regrading that please suggest me.