Can't load a few experiment files

I have two experiments that cannot be loaded into igor. They were both last accessed about a year ago. In one case, I simply get "This does not appear to be a valid IGOR experiment file". The other experiment starts to open, but then generates the following log:

*** Igor was unable to fully recreate the experiment. ***
This notebook contains diagnostics to help you understand the problem.
You can kill this notebook when you no longer need the diagnostics.

IMPORTANT:
Some waves, procedures or other data were not loaded into the current experiment.
Therefore, if you save the current experiment DO NOT OVERWRITE any existing files.
It is OK to save the experiment. Just use a new name for the file.

While reading a record from the packed experiment file an error occurred the following error occurred: incompatible Igor binary version.
While reading a record from the packed experiment file an error occurred
Skipping bad record: recordNum=34, startPos=1726636, recordType=superseded 3648, version=-3450, bytes=-358838835

Any ideas how to open these? I am stumped. The files are about 40 mb and 100 mb respectively, and I can upload them if necessary.
The most common cause of this is transferring a file via FTP in text mode rather than binary. This causes CR <-> LF conversions that corrupt binary data. In this case the only solution is to go to a backup.

If that does not explain the problem...

I think your files are on the large size to post here. Instead send a note to WaveMetrics support. Include your Igor version, OS and serial number. We will send you instructions for uploading to our FTP site and I will take a look at the files and see what I can make of them. However in most cases such files are not recoverable.

This is a good reminder to make frequent backups.
Thanks for the info. These files were never transferred via FTP as far as I can recall, but I am synchronizing files across machines using BitTorrent Sync. This hasn't been a problem for most of my Igor experiments, just a few I've come across. I'll try contacting WaveMetrics support next.
Quote:
but I am synchronizing files across machines using BitTorrent Sync.


I'm suspicious of any file system software that did not come with the system itself.

Compare the size of the file on the two machines. They should be the same. If they are the same, it does not guarantee that the transfer did not mess something up but if they are different it shows that the transfer caused a problem.
hrodstein wrote:
Quote:
but I am synchronizing files across machines using BitTorrent Sync.


I'm suspicious of any file system software that did not come with the system itself.

Compare the size of the file on the two machines. They should be the same. If they are the same, it does not guarantee that the transfer did not mess something up but if they are different it shows that the transfer caused a problem.


The files are indeed identical, but as you say no guarantee. I've been using this program to sync large amounts of data between 3 machines, and have only run into problems with these two Igor experiments - many more have been just fine! Anyway, if it is to blame or not, sounds like my chances of recovering these files is pretty slim?
Quote:
The files are indeed identical, but as you say no guarantee.


I presume you mean that the file sizes are identical.

Usually if the file sizes are the same, the file has not been munged, but it is not guaranteed.

If there is a copy of the file on the original machine, i.e., a copy that was never transferred, see if it opens correctly.

Quote:
Anyway, if it is to blame or not, sounds like my chances of recovering these files is pretty slim?


Sometimes I can recover part or most of the file. It depends on the nature of the problem.
billyblack wrote:
hrodstein wrote:
Quote:
but I am synchronizing files across machines using BitTorrent Sync.


I'm suspicious of any file system software that did not come with the system itself. ...


The files are indeed identical, but as you say no guarantee. I've been using this program to sync large amounts of data between 3 machines, and have only run into problems with these two Igor experiments - many more have been just fine! Anyway, if it is to blame or not, sounds like my chances of recovering these files is pretty slim?


Have you tried to archive the files (ZIP), transfer the archive, unpack, and open?

Following on Howard's comment, have you tried an ftp transfer?

--
J. J. Weimer
Chemistry / Chemical & Materials Engineering, UAHuntsville