nelson c said:
This is very strange. Now it seems to be working well (without restarting the program).
When I wrote the post did not work at all, he had made a screenshot, but deleted it because I thought it was not necessary.
When it happens again I'll upload a screenshot.
Please let me know if you have more information about the issue. To fix this, the following information is needed: a screenshot and, when it stops appearing, does it happen permamently, or if you start another track, the bar appears again?