Are you coping old files over the new avast installation? I mean, avast4.mdb or avast4.ini file, or whatever other file on avast setup folder?
Initialization of storage functions is wrong!
This is an error message related, generally, to old storage methods.
Since version 4.7.807 a new data storage called SQLT is used by avast! Which version are you using?
E:\Säkerhet\
I think the problem could be in the non default acented caracther on the path: ä
I have already this problem in the past.
Alwil does not solve it… it comes back from time to time :-\ 
If I try right now, I’ll have problems too… I gave up to use acented caracthers on the avast installation path :-\