Learning Forum

[kelvin.k.kong]

Dear staff and fellow users, After successfully ran a simulation in Fluent Solutions, I clicked on File > Write > Case & Data to save my progress.
Is that the correct way of saving? Because when I tried to open it: File > Read > Case & Data:

 I was unable to open it, and this message popped up in the console: 

> Fast-loading "C:\PROGRA~1\ANSYSI~1\v251\fluent\fluent25.1.0\addons\afd\lib\hdfio.bin"

Done.

HDF5-DIAG: Error detected in HDF5 (1.12.2) MPI-process 0:

#000: C:\.conan\888d91\1\hdf5-1.12.2\src\H5F.c line 620 in H5Fopen(): unable to open file

major: File accessibility

minor: Unable to open file

#001: C:\.conan\888d91\1\hdf5-1.12.2\src\H5VLcallback.c line 3502 in H5VL_file_open(): failed to iterate over available VOL connector plugins

major: Virtual Object Layer

minor: Iteration failed

#002: C:\.conan\888d91\1\hdf5-1.12.2\src\H5PLpath.c line 579 in H5PL__path_table_iterate(): can't iterate over plugins in plugin path '(null)'

major: Plugin for dynamically loaded library

minor: Iteration failed

#003: C:\.conan\888d91\1\hdf5-1.12.2\src\H5PLpath.c line 713 in H5PL__path_table_iterate_process_path(): can't open directory

major: Plugin for dynamically loaded library

minor: Can't open directory or file

#004: C:\.conan\888d91\1\hdf5-1.12.2\src\H5VLcallback.c line 3351 in H5VL__file_open(): open failed

major: Virtual Object Layer

minor: Can't open object

#005: C:\.conan\888d91\1\hdf5-1.12.2\src\H5VLnative_file.c line 97 in H5VL__native_file_open(): unable to open file

major: File accessibility

minor: Unable to open file

#006: C:\.conan\888d91\1\hdf5-1.12.2\src\H5Fint.c line 1999 in H5F_open(): unable to read root group

major: File accessibility

minor: Unable to open file

#007: C:\.conan\888d91\1\hdf5-1.12.2\src\H5Groot.c line 228 in H5G_mkroot(): can't check if symbol table message exists

major: Symbol table

minor: Can't get value

#008: C:\.conan\888d91\1\hdf5-1.12.2\src\H5Omessage.c line 845 in H5O_msg_exists(): unable to protect object header

major: Object header

minor: Unable to protect metadata

#009: C:\.conan\888d91\1\hdf5-1.12.2\src\H5Oint.c line 1051 in H5O_protect(): unable to load object header

major: Object header

minor: Unable to protect metadata

#010: C:\.conan\888d91\1\hdf5-1.12.2\src\H5AC.c line 1426 in H5AC_protect(): H5C_protect() failed

major: Object cache

minor: Unable to protect metadata

#011: C:\.conan\888d91\1\hdf5-1.12.2\src\H5C.c line 2370 in H5C_protect(): can't load entry

major: Object cache

minor: Unable to load metadata into cache

#012: C:\.conan\888d91\1\hdf5-1.12.2\src\H5C.c line 7315 in H5C__load_entry(): incorrect metadata checksum after all read attempts

major: Object cache

minor: Read failed

#013: C:\.conan\888d91\1\hdf5-1.12.2\src\H5Ocache.c line 203 in H5O__cache_get_final_load_size(): can't deserialize object header prefix

major: Object header

minor: Unable to decode value

#014: C:\.conan\888d91\1\hdf5-1.12.2\src\H5Ocache.c line 1202 in H5O__prefix_deserialize(): bad object header version number

major: Object header

minor: Wrong version number

 

999999: mpt_accept: warning: connection timed out after 120 seconds

Error in the fluent (fl) process : ended abnormally

 

When I tried the second time:

Fast-loading "C:\PROGRA~1\ANSYSI~1\v251\fluent\fluent25.1.0\addons\afd\lib\hdfio.bin"

Done.

HDF5-DIAG: Error detected in HDF5 (1.12.2) MPI-process 0:

#000: C:\.conan\888d91\1\hdf5-1.12.2\src\H5F.c line 620 in H5Fopen(): unable to open file

major: File accessibility

minor: Unable to open file

#001: C:\.conan\888d91\1\hdf5-1.12.2\src\H5VLcallback.c line 3502 in H5VL_file_open(): failed to iterate over available VOL connector plugins

major: Virtual Object Layer

minor: Iteration failed

#002: C:\.conan\888d91\1\hdf5-1.12.2\src\H5PLpath.c line 579 in H5PL__path_table_iterate(): can't iterate over plugins in plugin path '(null)'

major: Plugin for dynamically loaded library

minor: Iteration failed

#003: C:\.conan\888d91\1\hdf5-1.12.2\src\H5PLpath.c line 713 in H5PL__path_table_iterate_process_path(): can't open directory

major: Plugin for dynamically loaded library

minor: Can't open directory or file

#004: C:\.conan\888d91\1\hdf5-1.12.2\src\H5VLcallback.c line 3351 in H5VL__file_open(): open failed

major: Virtual Object Layer

minor: Can't open object

#005: C:\.conan\888d91\1\hdf5-1.12.2\src\H5VLnative_file.c line 97 in H5VL__native_file_open(): unable to open file

major: File accessibility

minor: Unable to open file

#006: C:\.conan\888d91\1\hdf5-1.12.2\src\H5Fint.c line 1999 in H5F_open(): unable to read root group

major: File accessibility

minor: Unable to open file

#007: C:\.conan\888d91\1\hdf5-1.12.2\src\H5Groot.c line 228 in H5G_mkroot(): can't check if symbol table message exists

major: Symbol table

minor: Can't get value

#008: C:\.conan\888d91\1\hdf5-1.12.2\src\H5Omessage.c line 845 in H5O_msg_exists(): unable to protect object header

major: Object header

minor: Unable to protect metadata

#009: C:\.conan\888d91\1\hdf5-1.12.2\src\H5Oint.c line 1051 in H5O_protect(): unable to load object header

major: Object header

minor: Unable to protect metadata

#010: C:\.conan\888d91\1\hdf5-1.12.2\src\H5AC.c line 1426 in H5AC_protect(): H5C_protect() failed

major: Object cache

minor: Unable to protect metadata

#011: C:\.conan\888d91\1\hdf5-1.12.2\src\H5C.c line 2370 in H5C_protect(): can't load entry

major: Object cache

minor: Unable to load metadata into cache

#012: C:\.conan\888d91\1\hdf5-1.12.2\src\H5C.c line 7315 in H5C__load_entry(): incorrect metadata checksum after all read attempts

major: Object cache

minor: Read failed

#013: C:\.conan\888d91\1\hdf5-1.12.2\src\H5Ocache.c line 203 in H5O__cache_get_final_load_size(): can't deserialize object header prefix

major: Object header

minor: Unable to decode value

#014: C:\.conan\888d91\1\hdf5-1.12.2\src\H5Ocache.c line 1202 in H5O__prefix_deserialize(): bad object header version number

major: Object header

minor: Wrong version number

 

999999: mpt_accept: warning: connection timed out after 120 seconds

Error in the fluent (fl) process : ended abnormally

 

Note: Saved with 2025 R1. Trying to open in 2025 R1.

 Thanks!

[Rob]

That's correct. Are you running Fluent standalone? Can you save to a non OneDrive folder to check the folder set up. Finally, how are you for disc space and RAM; monitor the latter as you save the files?

[kelvin.k.kong]

 

Hi Rob,

Yes, I’m using Fluent standalone. Should I use Workbench to launch Fluent? 

I’m part of a university team, and our files are saved on Onedrive.
I saved the file with the laptop that I tried to open my saved file with, so file should be on my computer. (not waiting to be downloaded from the Onedrive Cloud)

My laptop that I run simulations, my 1TB hardrive is about half full, 128GB RAM. (Recent simulations used between 64 – 66GB ram, usually.)

Thanks.

 

[Rob]

OK, thanks. Use Fluent in standalone mode and save locally. If you can save to a non-Onedrive folder try that. RAM sounds good. Note, Onedrive is also a folder on the computer and I've seen problems with some versions of Win10 & 11 trying to upload/scan large files as they're written which can cause problems, hence if you can save in D:/ or C:/ away from it. How many cores are you running on? 

[kelvin.k.kong]

Hey Rob,

I'm on the full ANSYS Mechanical Enterprise and CFD Enterprise license. Using Double precison, and max cores I can use on my laptop is 8 cores. (8 Performance cores).

[Rob]

So Win10/11?  The licence type isn't an issue here, it's something OS related. Does saving to the root folder help? 128MB RAM on a laptop - I need to talk to Ansys IT before my next replacement check! 

[kelvin.k.kong]

 

I’m using Windows 11 Pro. 

Saving to C:/ results in this:

After that, Fluent won't let me perform tasks, all of the tasks either goes blank, or something weird happening to them:

Examples:

Values disappears.

Overlap in texts.

Same with after I try to import the initial simulation that I saved. I have to close Fluent and open it back up to be able to do tasks again.

 

[Rob]

That looks to be a cortex related failure - ie the head & display node has failed. Try without all of the spaces and double check write permissions. 

What happens if you switch to Legacy for file IO in the Preferences?

[kelvin.k.kong]

Try saving the name of simulation no spaces, with underscores?

I'll try saving without spaces first. 

Then if that doesn't work, I will try both without spaces and the legacy setting.

[kelvin.k.kong]

 

 

 

Attempt 1:

When I tried to save with underscores (no spaces), it didn’t successfully save:

I saved Case & Data after initialization, before running the simulation. This is the file which I have been using to run simulations.
Strange, because I am able to open this file which is also in my Onedrive, but not the post-simulation one?!

Q1) After my run simulation, do I just save data only, since I already have a case file from before, which I’m assuming won’t change, will it?

Attempt 2: Changing to Legacy setting before saving with underscores:

Tried to save in .cas .dat files…

But got this message:

Attempt 3 – Save by allowing myself to write:

Didn’t save successfully.

 

Attempt 4 – With CFF: I tried to save my pre-simulation case and data file that’s on my Onedrive to my C drive:
Strange.

Attempt 5 – With Legacy. I tried to save my pre-simulation case and data file that’s on my Onedrive to my C drive:

Could all this also be because I didn't save my mesh file with underscores? But Fluent Solutions still read it, and saved my pre-simulation case and data file.

 

[kelvin.k.kong]

 

Update:

Started Fluent as “ran as Admin”. Ran another test simulation to 500 iterations and completed (other sims I stopped the simulation myself. Not sure if it makes any difference to my issue, but I’ll just be detailed).

I was able to successfully save into my C drive and Onedrive:

C drive:

Then, I was able to open both Test files (Case&Data) from my C drive and Onedrive.

 

[Rob]

I'll get install to look. The save files should use/call all of the same solver routines so permissions shouldn't change, but something is blocking the drive from the Error: sopenoutput message. 

Whilst you don't need to save case file every time it's a good habit to do so. If you reorder the mesh the case and data won't match so I always save both. It's easy to delete files afterwards, but impossible to save after the fact!