ServoDyn error

Good morning,

I am having issues with the initialisation of ServoDyn. I am receiving the error:

FAST_InitializeAll:SrvD_Init:BladedInterface_Init:The dynamic library
C:\Storage\BC\419_FES\FAST\CaseB\ServoData\DISCON.dll could not be loaded. Check that the file
exists in the specified location and that it is compiled for 64-bit applications.

FAST encountered an error during module initialization.
Simulation error level: FATAL ERROR

Aborting OpenFAST.

I have seen this issue raised many times in this forum and I have read all of the corresponding threads, for example:

I see the main solutions seem to be 1) correct the paths and 2) make sure you are using the correct 64/32 bit application.

I am using OpenFAST v1.0.0 x64 (I understand this is not the latest version of the software, but this project was started when it was the latest).

I am sure the file paths and names are correct and I have run this Servodyn file with the x64 OpenFAST v1.0.0 executable successfully on another computer, so I am sure it is compiled for 64-bit applications.

Could you please advise on any other potential solutions? One thought I had was potentially on the subject of the redistributable libraries. The computer on which I am trying to run this analysis has the redistributables for the 2020 Intel Fortran as OpenFAST v2.5.0 is primarily used on this pc. However, I wonder if OpenFAST v1.0.0 is having an issue as it is using these restributables, where it should be using an older version, could this be correct? If so, could you direct me to the correct redistributable libraries for OpenFAST v1.0.0, I imagine it 2017 or earlier as this is the version for OpenFAST v2.0.0, however I cannot see a link specifically for v1.0.0 on And secondly, if v1.0.0 should be using an older version of the redistributable libraries, how would I change which redistributable libraries the executable is using to make sure it using the older version?

Thanks in advance,

Dear Bruce,

Not all precompiled binary executables of OpenFAST require the Intel redistributable libraries; the ones that do were built to require dynamic libraries from Intel rather than being compiled with Intel static libraries. I don’t recall what OpenFAST v1.0.0 requires, but regardless, I would expect that you’d receive a different error if the problem was missing or incorrect Intel redistributable libaries, e.g. an “Entry Point Not Found” error, as discussed here:

For the error you are receiving, I’ve only seen this problem arise with one of the two solutions you’ve stated. Can you clarify what the source of the DISCON.dll you are using is? Is this something NREL has provided or did you compile it yourself?

Best regards,