I just tried updating from NC 13.0.3 to 13.0.4.
First error message came when creating the backup, then I restarted the process.
Since then I get a white page with the message Update in process .
Here is the log
2018-06-15T04:30:28+0200 Qi2EO90txA [info] storage location: /home/users/zsemberi/www/cloud/data/updater-ochycxll0hj9/downloads/ 2018-06-15T04:30:29+0200 Qi2EO90txA [info] end of verifyIntegrity() 2018-06-15T04:30:29+0200 Qi2EO90txA [info] endStep("6") 2018-06-15T04:30:29+0200 tocYUKvaPD [info] request to updater 2018-06-15T04:30:29+0200 tocYUKvaPD [info] currentStep() 2018-06-15T04:30:29+0200 tocYUKvaPD [info] Step 6 is in state "end". 2018-06-15T04:30:29+0200 tocYUKvaPD [info] POST request for step "7" 2018-06-15T04:30:29+0200 tocYUKvaPD [info] startStep("7") 2018-06-15T04:30:29+0200 tocYUKvaPD [info] extractDownload() 2018-06-15T04:30:29+0200 tocYUKvaPD [info] storage location: /home/users/zsemberi/www/cloud/data/updater-ochycxll0hj9/downloads/ 2018-06-15T04:30:39+0200 tocYUKvaPD [info] end of extractDownload() 2018-06-15T04:30:39+0200 tocYUKvaPD [info] endStep("7") 2018-06-15T04:30:39+0200 pqSxkjuh3B [info] request to updater 2018-06-15T04:30:39+0200 pqSxkjuh3B [info] currentStep() 2018-06-15T04:30:39+0200 pqSxkjuh3B [info] Step 7 is in state "end". 2018-06-15T04:30:39+0200 pqSxkjuh3B [info] POST request for step "8" 2018-06-15T04:30:39+0200 pqSxkjuh3B [info] startStep("8") 2018-06-15T04:30:39+0200 pqSxkjuh3B [info] replaceEntryPoints() 2018-06-15T04:30:39+0200 pqSxkjuh3B [info] replace index.php 2018-06-15T04:30:39+0200 pqSxkjuh3B [info] replace status.php 2018-06-15T04:30:39+0200 pqSxkjuh3B [info] replace remote.php 2018-06-15T04:30:39+0200 pqSxkjuh3B [info] replace public.php 2018-06-15T04:30:39+0200 pqSxkjuh3B [info] replace ocs/v1.php 2018-06-15T04:30:39+0200 pqSxkjuh3B [info] replace ocs/v2.php 2018-06-15T04:30:39+0200 pqSxkjuh3B [info] end of replaceEntryPoints() 2018-06-15T04:30:39+0200 pqSxkjuh3B [info] endStep("8") 2018-06-15T04:30:39+0200 8zY6Zv0ckD [info] request to updater 2018-06-15T04:30:39+0200 8zY6Zv0ckD [info] currentStep() 2018-06-15T04:30:39+0200 8zY6Zv0ckD [info] Step 8 is in state "end". 2018-06-15T04:30:39+0200 8zY6Zv0ckD [info] POST request for step "9" 2018-06-15T04:30:39+0200 8zY6Zv0ckD [info] startStep("9") 2018-06-15T04:30:39+0200 8zY6Zv0ckD [info] deleteOldFiles() 2018-06-15T04:30:45+0200 8zY6Zv0ckD [info] config sample exists 2018-06-15T04:30:45+0200 8zY6Zv0ckD [info] themes README exists 2018-06-15T02:41:36+0000 lDAL1a6dOi [info] updater cli is executed 2018-06-15T02:41:36+0000 lDAL1a6dOi [info] currentStep() 2018-06-15T02:41:36+0000 lDAL1a6dOi [info] Step 9 is in state "start". 2018-06-15T02:42:56+0000 f1GREUlS0E [info] updater cli is executed 2018-06-15T02:42:56+0000 f1GREUlS0E [info] currentStep() 2018-06-15T02:42:56+0000 f1GREUlS0E [info] Step 9 is in state "start". 2018-06-15T02:44:33+0000 AcJKL8oJyF [info] updater cli is executed 2018-06-15T02:44:33+0000 AcJKL8oJyF [info] currentStep() 2018-06-15T02:44:33+0000 AcJKL8oJyF [info] Step 9 is in state "start". 2018-06-15T02:47:19+0000 iM03b0Emrc [info] updater cli is executed 2018-06-15T02:47:19+0000 iM03b0Emrc [info] currentStep() 2018-06-15T02:47:19+0000 iM03b0Emrc [info] Step 9 is in state "start". 2018-06-15T02:53:49+0000 9QR6KDzNoZ [info] updater cli is executed 2018-06-15T02:53:49+0000 9QR6KDzNoZ [info] currentStep() 2018-06-15T02:53:49+0000 9QR6KDzNoZ [info] Step 9 is in state "start".