st: merge error - not Stata format

[June Bridge <junebridge25@gmail.com>]

Hello,

I've run into a problem trying to merge two data sets.  Both are in
stata format (dta files), but when I try to merge them, like this:

use dataset1.dta
merge m:1 id year using dataset2.dta

I get an error message like this:
file /projectfolder/temp/St90704.00000b not Stata format

It seems like one of the temp files that is created during the merge
is somehow in the wrong format? The strange thing is, this only
started happening yesterday - I've used the same code before without a
problem. Has anyone faced this problem before? Any idea how to fix it?
Is there any other information that could help?

As as FYI, I'm using Stata MP 12.1, accessing it through my university
(on Linux).  I've also reached out to my university's IT department
for help, but I thought I'd ask here too in case somebody else has run
into this problem in the past.

Thanks so much,
June
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