build doc search db failure

Exactly what does "Could not write search database" mean? I'm using builddocsearchdb() and it's worked nicely in the past but now all of a sudden I'm getting this unclear error message. This system is 2008b Matlab (7.7.0.471) and JVM 1.6.0_04. Any help would be appreciated. -Rick

[Sebastian]

I have the same problem here with R2015a, even if the same command for the same documentation is working for R2010b, R2013b and R2014b.

[Dr.-Ing. Volker Sellmeier]

Same problem here with R2015b. It works nicely in R2014b, which is installed on the same computer. Any help?