Template file not found: template:layout.guest after updating to NC15 from NC14

Hello!

After updating through web-site (not manually) to NC15 from NC14 I got the Internal Server Error error: "template file not found: template:layout.guest"

What the problem it could be?

The full log is below:

{
“reqId”: “yOdcbRuRou4qk6h2WYB6”,
“level”: 3,
“time”: “2019-01-23T00:20:49+00:00”,
“remoteAddr”: “x.x.x.x”,
“user”: “user”,
“app”: “core”,
“method”: “GET”,
“url”: “/disk/index.php/apps/files/”,
“message”: {
“Exception”: “Exception”,
“Message”: “template file not found: template:layout.guest”,
“Code”: 0,
“Trace”: [
{
“file”: “/var/www/html/disk/lib/private/legacy/template.php”,
“line”: 180,
“function”: “find”,
“class”: “OC\Template\TemplateFileLocator”,
“type”: “->”,
“args”: [
“layout.guest”
]
},
{
“file”: “/var/www/html/disk/lib/private/legacy/template.php”,
“line”: 87,
“function”: “findTemplate”,
“class”: “OC_Template”,
“type”: “->”,
“args”: [
“”,
“core”,
“layout.guest”
]
},
{
“file”: “/var/www/html/disk/lib/private/TemplateLayout.php”,
“line”: 119,
“function”: “__construct”,
“class”: “OC_Template”,
“type”: “->”,
“args”: [
“core”,
“layout.guest”,
“”,
false
]
},
{
“file”: “/var/www/html/disk/lib/private/legacy/template.php”,
“line”: 211,
“function”: “__construct”,
“class”: “OC\TemplateLayout”,
“type”: “->”,
“args”: [
“error”,
“”
]
},
{
“file”: “/var/www/html/disk/lib/private/Template/Base.php”,
“line”: 132,
“function”: “fetchPage”,
“class”: “OC_Template”,
“type”: “->”,
“args”: []
},
{
“file”: “/var/www/html/disk/lib/private/legacy/template.php”,
“line”: 360,
“function”: “printPage”,
“class”: “OC\Template\Base”,
“type”: “->”,
“args”: []
},
{
“file”: “/var/www/html/disk/index.php”,
“line”: 69,
“function”: “printExceptionErrorPage”,
“class”: “OC_Template”,
“type”: “::”,
“args”: [
{
class”: “Exception”
},
500
]
}
],
“File”: “/var/www/html/disk/lib/private/Template/TemplateFileLocator.php”,
“Line”: 56,
“CustomMessage”: “–”
},
“userAgent”: “Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36”,
“version”: “15.0.2.0”
}

This method helped me:
https://forum.owncloud.org/viewtopic.php?p=104222#p104222