This page describes how to fix a bug in the dll of EnergyPlus 7.1.0, build12 for Windows that may occur when exchanging a large amount of data in each time step. The error message that EnergyPlus writes to its .err file is

 ExternalInterface starts first data exchange.
 Error: No digits were found in getDoubleCheckError.
 Further characters after number:
 Sending EXIT_FAILURE = : 1
 **FATAL:Error in ExternalInterface: Check EnergyPlus *.err file.

To fix the bug, proceed as follows:

Windows

1. Install the BCVTB version 1.1.0.

2. Download the bcvtb.dll for your architecture and copy it to the EnergyPlus directory, such as C:\Program Files\EnergyPlus-7-1-0. This will replace the existing file with the same name.

   1. Click on bcvtb_win32.zip to download the bcvtb.dll for Windows 32 bit.

   2. Click on bcvtb_win64.zip to download the bcvtb.dll for Windows 64 bit.