"Invalid license (538), please reinstall from MQL5 Market" This error comes when trying to attach mql5 market bot. Either an indicator or EA. MQL5 Market ensures secure transactions, and products are typically protected by licensing mechanisms to prevent unauthorized use. There are several ways to avoid invalid license error.
- use mql5 market to buy the bot (Recommended method)
- get a working DLL file. This tricks the metatrader software that the EA/Indicator is authorized by mql5 market.
- Get a cracked copy of the bot.
Not conclusive, but I just gave my point of view.