Column not found: 1054 Unknown column 'b.parent' in 'field list'

You need to apply the patch in #1713570: Change Browscap database schema to match the columns defined in the default XML schema from the browscap data.
This information could be found in /mobile_tools_browscap/README.txt, by the way.

Remarks re drupal.org workflow:

• please assign an issue to yourself only when you plan to write a patch or do other work on the issue;
• please set an issue to 'needs review' only when there is something to review (e.g., a patch). Thank you!

(this is probably 'Closed (works as designed)' but I'll leave the decision to the maintainers :)

If mobile tools to function correctly depends on this patched code, then I would think the same rules apply as library dependencies where a warning appears in the Status page and often even a message in the help region and on the command line when using drush.

Especially when you install with drush, dependency modules like browsercap are installed on-the-fly and it is not very obvious that you should patch something, when there is no warning displayed.

I changed to bug status because numerous user reports contradict if the offered patch solutions work for them. There is no agreement nor an accepted dev version. Until then this issue should remain in active bug status. Functionality remains broken until there is working (dev) release of the depending module.

Working on this issue

I am able to reproduce the issue.It's a fatal error and fixed the issue. I am attaching the patch.

Fixes works for me....

There's no patch here so it's not RTBC. I think it's a duplicate of #1713570: Change Browscap database schema to match the columns defined in the default XML schema from the browscap data. People interested in the topic should work on that issue.