# Error while Integrating with mathematica algorithm

Hi,

Trying once more to integrate with the mathematica algorithm since a long time - did work before - I realized that now it gives me an error:

```
integrate(10*x-3, x, algorithm="mathematica_free")
```

And it returns

```
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "_sage_input_12.py", line 10, in <module>
exec compile(u'open("___code___.py","w").write("# -*- coding: utf-8 -*-\\n" + _support_.preparse_worksheet_cell(base64.b64decode("aW50ZWdyYXRlKDEwKngtMywgeCwgMSwgMywgYWxnb3JpdGhtPSdtYXRoZW1hdGljYV9mcmVlJyk="),globals())+"\\n"); execfile(os.path.abspath("___code___.py"))
File "", line 1, in <module>
File "/tmp/tmp0ZIVPP/___code___.py", line 3, in <module>
exec compile(u"integrate(_sage_const_10 *x-_sage_const_3 , x, _sage_const_1 , _sage_const_3 , algorithm='mathematica_free')" + '\n', '', 'single')
File "", line 1, in <module>
File "/usr/lib/sagemath/local/lib/python2.7/site-packages/sage/misc/functional.py", line 664, in integral
return x.integral(*args, **kwds)
File "sage/symbolic/expression.pyx", line 11660, in sage.symbolic.expression.Expression.integral (/usr/lib/sagemath//src/build/cythonized/sage/symbolic/expression.cpp:64426)
File "/usr/lib/sagemath/local/lib/python2.7/site-packages/sage/symbolic/integration/integral.py", line 771, in integrate
return integrator(expression, v, a, b)
File "/usr/lib/sagemath/local/lib/python2.7/site-packages/sage/symbolic/integration/external.py", line 67, in mma_free_integrator
page = page[page.index('"inputForm"'):page.index('"outputForm"')]
ValueError: substring not found
```

A "substring not found". Oh. What does it mean and how am I supposed to fix that? I add it totally worked before.

Thanks

The integrals Wolfram website may have changed its format again?

That's what I thought. Actually, I haven't been using this algorithm since... I began using sage. So, it had indeed time to change in the meanwhile. But it seems like sage and its scripts can't find the instructions (kind of a protocol) to call mathematica on the internet... rather than mathematica returning an error.