Hi – I'm learning Houdini using apprentice (Houdini 10.0.249.5) on windows xp 32bit. Just tried rendering via a mantra node and get this error in the Houdini consolde:

Warning: invalid .mplay_lock file detected
Warning: invalid .mplay_lock file detected
mantra: Could not open imager

Then mplay opens but shows a blank frame.

When I try to render again, mantra opens up an instance in background but doesn't try rendering anything.

Sounds like something similar is happening to other users… would love to render something with this package (!)

Mark

Try removing the .mplay_lock file from your $HOME/houdini10.0 directory, and see if that makes any difference. They are supposed to be automatically deleted, but it sounds like some of the problems you're having may be interfering with that.

hi - thanks. There's no file of that name in that directory. Just in case I deleted the directory so houdini re-ran the post install initialization, and same problem occurs.

Do a full search for .mplay_lock on your harddrive. Perhaps windows has put that file someplace else.
I'd probably search the Registry as well.

OK – searched the drive and got nothing. Searched the registry and there's a couple occurrences in there, but I've no idea what to do with that.

I have to edit the registry to get houdini to render? nice. Is this kind of thing common with houdini, in users' experiences?

OK so I deleted any reference to .mplay_lock in the registry, opened houdini and rendered and it worked – thanks for the suggestion, much appreciated.

No it's not.

We run windows in a production environment every day… I've yet to see any mission critical failures that are platform specific.

Rest assured, if we find any, we'll scream, and SESI (as usual) will deal with them promptly.

Best,

G

great to know, thx

Hi,

No, this is not common and you shouldn't have to search through the registry as it's just a regular file.

Personally, I've never seen the error before but it does happen to a few users and unfortunately, you are one of them.

Since I'm using WinXP 32bit on my laptop, let's see if we can work this out. First thing I would like you to try is to start mplay from Houdini through the Render menu > MPlay > Listen for Renders.

After MPlay starts, please go to your houdini10.0 directory (usually located in C:\Documents and Settings\your_username\My Documents) and see if there is a .mplay_lock.YOURMACHINENAME file. The file is created only when MPlay starts. If there is, try to render a file and see if it works.

Please let me know how it goes and we'll take it from there.

Good luck!

Cheers!
steven

hi Steven,
thanks for your response. After deleting those entries from the registry, I was able to render without issue, but I followed along with what you suggested and indeed there is a file now in that directory with the name you indicated. And I re-did a render and it worked fine. So….. I guess it's ok.

Weird about the registry entry.

So what's the .mplay_lock file about? Just a file associating mplay with that instance of houdini?

Hi,

I'm glad you can render now. It's really weird about the registry entries because I don't find them when I do a registry search.

As for the .mplay_lock file, it contains the Process ID of mplay when it starts and another Process ID as well. I believe mantra uses this file to determine which mplay to render to because you can have multiple mplay windows and you can control which one to Listen for Renders.

To see it in action, you can go to the Render menu in mplay > Disconnected and the .mplay_lock file is gone. Select Render menu > Listen for Renders and the .mplay_lock file is back again.

Cheers!
steven

I see, ok that makes sense. Thanks again.

mstasiuk
OK so I deleted any reference to .mplay_lock in the registry, opened houdini and rendered and it worked – thanks for the suggestion, much appreciated.

How did these registry entries look like?

Well, I don't know much about the registry or regedit.exe tool, so I'll just describe my steps and what I saw:
- Started up regedit.com
- Edit > find and entered .mplay_lock
- in the right-hand panel, 2 occurrences were found, showing name/type/data with name being something like 001 or 000 and data being .mplay_lock
- right-click on each and delete

Then when I tried to render, mplay opened and the render worked.

Maybe useful to know, just before I installed houdini 10 apprentice, I uninstalled houdini apprentice HD 9.1. Altho I played around a little bit with 9.1, I can't recall if I ever tried rendering. Possibly the issue actually lies with the H9.1 install and H10 saw that relic data and got confused. Anyway, now you know everything I know.

Dear Readers:

I was directed to this post by a Houdini user who thought my problem might be fixed by taking the steps mentioned above.

Unfortunately, I could not find “mplay_lock” in the registry so I couldn't delete the reference and I still can't render. I see that an .mplay_lock.blah file gets created when I try to run a View>Mantra. But the Mplay shows a black image (and not because I don't have lights in the scene)–in other words nothing rendered.

How do I fix this? Is this an installation issue or a config-file issue?

Sincerely,
markerline

Hello ,
everybody
iam new to 3d trying to learn houdini so installed 10.0.595 apprentice,
I also have the same problem as above members said , i didn't got anything in registry ,but i found 1 file named .mplay_lock in user folder and i deleted it but the error doesn't go it pops up every time when i try to renderi have attached the screen shot how to solve this kindly help

regards