ISSUE: There is a problem with this Windows Installer package

[Eggplantus]

I'm getting this error when trying to install Calibre 64-bit v0.9.26 on my Windows 7 SP1 64-Bit:



If I then try to open Calibre and try opening the Quick Start Guide, I get this error:

calibre, version 0.9.26
ERROR: Could not open ebook: [Error 5] Access is denied: u'C:\\Users\\Eggplantus\\AppData\\Local\\Temp\\calibre_u_ckls\\tv88xv_ebook_iter'

Traceback (most recent call last):
  File "site-packages\calibre\gui2\viewer\main.py", line 40, in run
  File "threading.py", line 504, in run
  File "site-packages\calibre\ebooks\oeb\iterator\book.py", line 99, in __enter__
  File "site-packages\calibre\customize\conversion.py", line 234, in __call__
  File "site-packages\calibre\__init__.py", line 441, in __enter__
WindowsError: [Error 5] Access is denied: u'C:\\Users\\Eggplantus\\AppData\\Local\\Temp\\calibre_u_ckls\\tv88xv_ebook_iter'

I have ActiveState ActivePython 2.7 (32-bit) installed as well as PyCrypto 2.6 for Python 2.7 32bit.

[Eggplantus]

I'm testing out the solution found at Superuser.com:

In my case, the DLL wasn't missing--the installer didn't have permissions to access the folder. I didn't try running the installer as an administrator--this didn't make sense to me considering I was already using an admin account and would have expected UAC to handle privileges elevation. Anyway, like many things in Windows, this whole thing is a bit of a mystery to me. Nevertheless, after going to Properties > Security on the C:\Users\x\AppData\Local\Temp folder and giving that Everyone the Full control permission, installers that previous had been failing now worked! Hooray!

UPDATE: You can also give yourself (your user name) the full control, not Everyone.

Here's the steps:

• Right-click the file or folder, and then click Properties.
  
• Click the Security tab, and then click Edit.

Do one of the following:

• To set permissions for a user that is not listed under Group or user names, click Add, type the name of the user or group, click OK, select the permissions, and then click OK.
  
• To change or remove permissions from an existing group or user, click the name of the group or user, select the permissions, and then click OK.

[Weezos_Gurl]

im also having this issue and i cant seem to figure out what to do in order to fix it. only difference that mine says "This installation package could not be opened. Contact the application vendor to verify that this is a valid Windows installer package" can someone please help me

[HarryT]

That sounds like a failed download. Empty your browser cache and download it again.

[JSWolf]

Or try a different browser. I have no problem downloading Calibre using Firefox.

[Eggplantus]

@Weezos_Gurl:

Install the latest version of CCleaner and run the Cleaner. Reboot your computer and then try again.