I can't compile my EAs after the recent compiler updates

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Hello everyone. I need your help!

I can't compile my EAs after updating the compiler. My current version is 5.00, build 5200 (August 1, 2025), and I'm not sure when it started failing, but I can't compile any of my EAs, not even the ones already running in production without errors.

I'm now getting a lot of errors that I didn't see before.

For example, I'm now getting the error "identifier 'NO' already used," and the related code is:

enum sino

{

NO =0, 

SI =1  
};

enum sinocontra
{
NO =0,
SI =1,
CONTRA=2
};

I see I'm using the same identifier in two different enumeration declarations. Of course, this works in all the compiled versions I've published (over 200), but recently it started failing.  What I would not want is to have to replace all the definitions with issues,  everywhere along my code (7000+ lines)

Any thoughs are welcome.

Thanks in advance.

 
orbaeztrader:

This happens because enum members share the same global namespace in MQL5.

Older builds allowed duplicates, but since build 5200 the compiler blocks them.

Solution: rename them with unique prefixes (e.g. SINO_NO, SC_NO) or wrap each enum in a namespace and qualify when using them.

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New MetaTrader 5 Platform Build 5200: Extended OpenBLAS support and enhanced control in MQL5

MetaQuotes, 2025.07.31 14:57

MQL5: Identical identifiers are now prohibited across different enumerations. An identifier declared in one enumeration can no longer be reused in another within the same scope:
enum A
  {
   Value
  };
  
enum B
  {
   Value  // error, name 'Value' is already used in enumeration A
  };
  
void OnStart(void)
  {
   enum C
     {
      Value // OK, 'Value' is not used within the OnStart scope
     };
  }
 
Miguel Angel Vico Alba #:

This happens because enum members share the same global namespace in MQL5.

Older builds allowed duplicates, but since build 5200 the compiler blocks them.

Solution: rename them with unique prefixes (e.g. SINO_NO, SC_NO) or wrap each enum in a namespace and qualify when using them.

Hello Miguel Angel. Thanks for your quick reply.

I'll have to rename a lot of definitions, but there is no any other alternative.

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