PTC Mathcad Prime "file type is not supported", error

[linda9]

Hello!

I just installed Mathcad Prime 5 on my computer two days ago and started working on a file. The first two days it was working perfectly, but today when I tried opening the file I got an error message stating that the type of file is not supported. I haven't made any updates since working on the file yesterday. I still need the content of the file and I am also wondering why this happened. I have attached the file. I am new to using Mathcad and I am hoping that someone can help me. (I am working on a MacBook with Windows running via Bootcamp). Thanks in advance!

[LucMeekes]

I'm afraid your file is lost. The zip file you attached has a size of only 319 bytes and occupies 0 kB on my disk.

It contains an .mcdx file with a supposed expanded size of 118 kB (100 % compression). You rported Prime will not open it. If renamed to .ZIP, it subsequently is not recognized as such. Bad file.

Your backup system and strategy becomes important to recover your work...

Success!
Luc

[linda9]

That's too bad but thank you very much for trying! 

[Werner_E]

Unfortunately I must confirm that the information in the file is lost (unless you have a backup somewhere).

The mcdx-file in the zip-file you sent with its size of 120169 bytes contains 120169 zero bytes. So there is no information which could be recovered.