Issue with site after installation

Hi, sorry fairly new to this, we have basically attempted to move our site from coldfusion 10, to lucee 5.3.7,48, we are and are having issues in terms of it recognising code that previously worked on coldfusion 10. I’m unsure if this is a setting thing but any advice would help massively, as were trying to get our head around this. an example of the issue is below, these is happening on multiple pages, many thanks

Lucee 5.3.7.48 Error (expression)
Message key [GAMEPARAMS] doesn’t exist
Stacktrace The Error Occurred in
/opt/lucee/tomcat/webapps/ROOT/PlayerRankings.cfm: line 58

56: FROM Player (NOLOCK)
57: WHERE rank > #l_rank#
58: AND lastLogin > '#application.gameParams.roundStartDate#'
59: AND lastLogin > DateAdd(d,-2,CURRENT_TIMESTAMP)
60: <cfif isDefined(“URL.letmein”)>

@noidea, If you have dot notation key means use bracket notation to retrieve the values.

Example:

<cfscript>
    test = {"gameParams.roundStartDate":"test"};
    writeDump(test["gameParams.roundStartDate"]);
</cfscript>

i already have the gameparams set in application.cfm as follows below, shouldnt it work in theory? as never had any issues on coldfusion 10, thanks for the advice.

<cfquery name="Application.GameParams" datasource="#Application.Datasource#">
  SELECT * FROM #Application.dbPrefix#_Game_Params (NOLOCK)
</cfquery>

<cfquery name="getGameVars" datasource="#application.datasource#">
	select * from game_variable (NOLOCK)
</cfquery>
<cfloop query="getGameVars">
	<cfset application["#getGameVars.variable#"] = getGameVars.value>
</cfloop>

@noidea, Could you check there is another application.cfc file available in the same ROOT folder?