EASIEST way to fix it and I just had this same problem. No need to uninstall Second Life.
0. Exit Second Life.
1.C:\Users\<The name of your user folder, which is your first name on your pc>\AppData\Local
copy and paste that in your folder on the file bar which is a long bar that shows you the path to your files.
Backspace what is in the <> and the <> then put your first name, should look like something like this.
C:\Users\Kate\AppData\Local
2. Look for Second life folder and delete all the cache files that's inside it, just do not delete the files with these names.
FILES YOU DO NOT DELETE.
First File) name.cache
Second File)keywords_lsl_b46a9fd1-58e5-c177-c4ee-fd0c9cdec9ea.llsd
Third File) index.db2.x.27076
Fourth File) data.db2.x.27076
If you do somehow delete these files, I am pretty sure Second Life client will resintall them automatically.