Attempt to concatenate string and function

I am trying to get the computers on my server to auto boot a specific script housed in a specific folder. I tried setting it up in the bios.lua, and the startup file within the rom but it does not seem to work. When I started digging into it I found I got the above message. Here is the code that I have as of right now:

overridesPath = "/rom/<folder>/overrides"
--folder holds files with a single word on line 1, word is the name of the program I want to run
overScriptsPath = "/rom/<folder>/scripts"
--location of all scripts that will run
customScriptsExists = fs.exists(overridesPath..os.getComputerID())

if customScriptExists then
   local customScripts = io.open(overridesPath..os.getComputerID(), "r")
   local scriptToRun = customScripts:read()
   while scriptToRun do
	  if (fs.exists(overScriptsPath..scriptToRun)) then
		 os.run( {}, overScriptsPath..scriptToRun)
	  else
		 print("Script "..scriptToRun.." for ID "..os.getComputerID().." does not exist. Please contact an Admin." )
	  end
   end
end

The error comes up on this line

customScriptsExists = fs.exists(overridesPath..os.getComputerID())

Any help would be greatly appreciated.

EDIT: forgot to say I'm using ComputerCraft 1.58

Did you copy and paste this or re-type it? You probably don't have the parentheses on os.computerID() in the actual code.

I copied this directly from my code and then edited out some of it. The parenthesis are there in my code.

Please directly paste the full code and the full error message.

Alright, I don't really know what I did differently, but the original error message I was getting is no longer coming up. However this is the startup file that comes with computercraft1.58, I figured this was the best place to put my custom startup script it.

--**********Outlandcraft Boot**********
overridesPath = "/rom/<SECRET>/overrides"
overScriptsPath = "/rom/<SECRET>/scripts"
customScriptsExists = fs.exists(overridesPath..os.getComputerID())

if customScripstExists then
   local customScripts = io.open(overridesPath..os.getComputerID(), "r")
   local scriptToRun = customScripts:read()
   while scriptToRun do
	  if (fs.exists(overScriptsPath..scriptToRun)) then
		 os.run( {}, overScriptsPath..scriptToRun)
	  else
		 print("Script "..scriptToRun.." for ID "..os.getComputerID().." does not exist. Please contact an Admiral." )
	  end
	  scriptToRun = customScript:read()
   end
end


local sPath = ".:/rom/programs"
if turtle then
   sPath = sPath..":/rom/programs/turtle"
else
   sPath = sPath..":/rom/programs/computer"
end
if http then
   sPath = sPath..":/rom/programs/http"
end
if term.isColor() then
   sPath = sPath..":/rom/programs/color"
end

shell.setPath( sPath )
help.setPath( "/rom/help" )

shell.setAlias( "ls", "list" )
shell.setAlias( "dir", "list" )
shell.setAlias( "cp", "copy" )
shell.setAlias( "mv", "move" )
shell.setAlias( "rm", "delete" )
shell.setAlias( "preview", "edit" )

if fs.exists( "/rom/autorun" ) and fs.isDir( "/rom/autorun" ) then
   local tFiles = fs.list( "/rom/autorun" )
   table.sort( tFiles )
   for n, sFile in ipairs( tFiles ) do
	  if string.sub( sFile, 1, 1 ) ~= "." then
		 local sPath = "/rom/autorun/"..sFile
		 if not fs.isDir( sPath ) then
			shell.run( sPath )
		 end
	  end
   end
end

This code did not work so when I went into lua and started trying to debug what exactly is not working I found that it is not finding the file (in this case just named 4 since that is the ID of the computer) in the path above. Could the fact that I made the file hidden by putting a "." in front matter, even though I put the actual folder name including the "." up in the beginning.

I have fixed the code, if anyone wants it here it is stripped down:

overridesPath = "/rom/overrides/overrides/"
overScriptsPath = "/rom/overrides/scripts/"
customScriptsExists = fs.exists(overridesPath..os.getComputerID())

if customScriptsExists then
local customScripts = io.open(overridesPath..os.getComputerID(), "r")
local scriptToRun = customScripts:read()
while scriptToRun do
if (fs.exists(overScriptsPath..scriptToRun)) then
os.run( {}, overScriptsPath..scriptToRun)
else
print("Script "..scriptToRun.." for ID "..os.getComputerID().." does not exist. Please contact an Admiral." )
end
end
end