[rrrlakin]

I purchased this book from the publisher.
It is in mobi format; I can read it on my kindle, or with my mobi-reader software on my windows 7 laptop. I can add it to my Calibre library, but when I try to open it in Calibre, either to read it or to covert it to epub, it tries very hard, but eventually goes to an error message: calibre, version 0.9.35
ERROR: Could not open ebook: Unknown error

Traceback (most recent call last):
File "site-packages\calibre\gui2\viewer\main.py", line 40, in run
File "threading.py", line 763, in run
File "site-packages\calibre\ebooks\oeb\iterator\book.py", line 99, in __enter__
File "site-packages\calibre\customize\conversion.py", line 239, in __call__
File "site-packages\calibre\ebooks\conversion\plugins\mobi_in put.py", line 34, in convert
File "site-packages\calibre\ebooks\mobi\reader\mobi6.py", line 171, in extract_content
File "re.py", line 151, in sub
MemoryError

According to the publisher, the book was originally formated in epub, then converted to mobi, so it would seem that . . .

Any thoughts or suggestions?