Calculating two sheets at the same time?

[ptc-4310378]

Should one stay away from calculating two sheets at the same time?

I was working on one sheet with another one calculating in the background. An error (something about exchange over domain not being possible) occured when recalculating the active sheet. The background sheet stalled with the same error.

I had seven sheets opened at that time. I closed them all to see if a restart would reactivate the two sheets with errors, but all seven failed when I tried to reopen them: five with corruped file messages and two with invalid XML file error.

Thanks to a recent back up, this was only a half day of work loss, but still a rather shocking experience!

Autosave was no help either.

[VladimirN]

What version of Mathcad? Can you upload your worksheets?

[ptc-4310378]

Mathcad 15.

Unfortunately, all the files opened at the time of the "stall" (there was no actual crash, just several error messages and files not calculating anymore) were corrupted and I couldn't open them anymore.

Did not think about keeping them for forensics......sorry. I discarded them and went back to older back up. I am in the middle of a exam/project right now, and I am trying to make up for the lost time rebuilding the file. I'll be through in two weeks and will give a try then with two similar files and see if the problem occurs again.

[RichardJ]

If this happens to you a solution would be to open more then one instance of Mathcad. They should run in their own separate spaces and not interfere with each other.

It's odd that you seem to get this worksheet corruption problem a lot. It has never happened to me (famous last words?)

[KrisR]

Oh, Richard.....

Now you've jinxed yourself!

[VladimirN]

Each individual run of Mathcad requires a separate license to run the program.

[RichardJ]

Each individual run of Mathcad requires a separate license to run the program.

I just launched four concurrent copies of Mathcad with no problems.

[VladimirN]

Just forgot to mention that I use "Floating" license for Mathcad.

[RichardJ]

That seems like a big limitation of a floating license!

[KrisR]

I think I'd check into that with my VAR. That seems like a really crummy thing for PTC to do if it's a floating license. Might be a bug.

[ptc-4310378]

Not sure if it is relevant, but the two sheets being calculated simultaneously before the crash (and burn) where two instances of the same sheet, just with different input data.

The error message, about being unable to exchange across domains, may infer that there could be confusion when a sheet calls for a variable that is also being handled by the other sheet?

[RichardJ]

There shouldn't be any confusion between variables in different sheets, and I have never seen any posts that would indicate such a bug exists. There's a first time for everything though