I assume you have the software installed in a non-English locale. If none of those fixes (perl command, web link etc.) worked for you, I think the best solution is to get Premiere Elements 12. We did hear a lot these issues in PrE10, but none in PrE11 and none so far in PrE 12, so they must have fixed it.
Retrieving that older corrupt project will really be a futile exercise though. Even if you open it, the perl commands might have only allowed you to open it and I am not sure how much it corrupts the content. (Removing keyframes etc.) If you have a working project, I suggest you take a copy of that right now because you are right that the results can be catastrophical if not fixed. You can do one of the following:
1. Uninstall the software and reinstall it, this time in English. None of the users had this reported in English AFAIK. You should be able to complete the project this time hopefully. This has not been tried in any of the earlier posts, but seems logical enough to give it a try.
2. Open it in a later version of Premiere Elements and you should be good to go. But you will have to buy the software, rather than use it in Trial mode because the Trial version applies watermarking on the clips (That's a visible mark on the clip that says "Adobe Premiere Elements Trial").
I never like to give the "Buy the newer version" as a solution, but this case could just be an exception...
The project that was destroyed was only a sketch board copy of my current project. That cost me 1 hour but that is OK. But I am in a time critical project and cannot afford this to happen again.
Our IT dept have centralized the installations - we are 35 000 users.To get windows 7 in 64 bits mode and Adobe Premiere Elements v 10 installed took over six months of pain and failures. I am the only one with this configuration. But I will ask them if they can install in English. I fear they will say no.
Is there any way to prevent future failures without getting English version - changing to decimal point insted of comma at system level?