Let a certificate already be present on my local machine, because I received some information on it via a PGP-signed email (you can easily do this by clicking in KMail on Show Details in the signed email and then click on the finger print that is displayed).

Now, try to import the key using the Kleopatra UI. Message:

"Certificate Import Result - Kleopatra [window title]

Detailed results of importing OpenPGP Certificate Server:
Total number processed: 0
Imported: 0"

(BTW: If somebody is going to fix this, there should be added an additional "from" in that sentence above.)

Running the whole thing in cmd line, everything looks good:

"user@kubuntu:~$ gpg2 --search-keys 0x1234567890ABCDEF
gpg: searching for "0x1234567890ABCDEF" from hkps server hkps.pool.sks-keyservers.net
(1)     John Doe <john.doe@doe.com>
         ...
          2048 bit RSA key 90ABCDEF, created: 2015-01-01, expires: 2017-01-01
Keys 1-1 of 1 for "0x1234567890ABCDEF".  Enter number(s), N)ext, or Q)uit > 1
gpg: requesting key 09ABCDEF from hkps server hkps.pool.sks-keyservers.net
gpg: key 09ABCDEF: public key "John Doe <john.doe@doe.com>" imported
gpg: 3 marginal(s) needed, 1 complete(s) needed, PGP trust model
gpg: depth: 0  valid:   1  signed:   1  trust: 0-, 0q, 0n, 0m, 0f, 1u
gpg: depth: 1  valid:   1  signed:   0  trust: 0-, 0q, 0n, 0m, 1f, 0u
gpg: next trustdb check due at 2015-12-21
gpg: Total number processed: 1
gpg:               imported: 1  (RSA: 1)"

It seems to be an internal problem of Kleopatra. Running the same thing with gpg (not gpg2) does the same.

Reproducible: Always

Steps to Reproduce:
1. Have a certificate on your local machine.
2. Search for certificate on keyservers.
3. Import (update) certificate from keyserver.

Actual Results:  
Total number processed: 0
Imported: 0

Expected Results:  
Total number processed: x
Imported: y

With x,y > 0 depending on the number and status of imported certificates.