On trying to install extension 'accentuate-1.0.0.oxt' I get an error

Error Message:
Add Extensions(s):
C:\users\jon\AppData\Roaming\LibreOffice\4\user\uno_packages\cache\uno_packages\luvmae8.tmp\Accentuate-1.0.0.oxt does not exist.

The oxt file does exist however, in my downloads folder, and this is where I directed libreOffice to get it from.
Anyone got any ideas?

LO Version: 4.3.5.2 Writer
Windows 7, English

I have similar problem. Did you ever find a solution?

I have a similar problem trying to install OOoLilyPond-0.4.0 or any newer version in my Libreoffice 6.2 (I use Ubuntu 16.04). It always worked fine.

I have this problem with LO 7.1.2.2 so it doesn’t seem outdated to me!

Thank you ROSt52. The extension does have the correct .oxt. I have had this extension installed before and it worked fine. Then for some reason I had to uninstall/reinstall LibreOffice and it was from this point that I could not put the ‘accentuate’ extension back.
Anyway, I have been able to install other extensions OK including another accenting extension that does the same job so at least I am able to do what I wanted - use accented characters.

Please check if the downloaded file really has the oxt-extension. If not check your download from the beginning carefully and look what is the file extension after the download. (This could be a Microsoft issue.)