Outlook iCal meeting invitation description issue

Question

I am sending iCal event invitation using php. Everything displays in proper manner and RVSP button displayed correctly. But description is cutting down after first line. For example if my description is:

The problem occurs when I have multiple lines in the description. 
If it contains the text for example I will only get in my outlook calendar 
description. The part after disappears.

The only first line displays like:

The problem occurs when I have multiple lines in the description.

If someone help me. I have already wrap the lines but after first line it will not displayed. Here is code snippet.

function ical_split($preamble, $value) {
    $value = trim($value);
    $value = strip_tags($value);
    $value = preg_replace('/\n+/', ' ', $value);
    $value = preg_replace('/\s{2,}/', ' ', $value);
    $preamble_len = strlen($preamble);
    $lines = array();
    while (strlen($value)>(74-$preamble_len)) {
        $space = (74-$preamble_len);
        $mbcc = $space;
        while ($mbcc) {
            $line = mb_substr($value, 0, $mbcc);
            $oct = strlen($line);
            if ($oct > $space) {
                $mbcc -= $oct-$space;
            }
            else {
                $lines[] = $line;
                $preamble_len = 1; // Still take the tab into account
                $value = mb_substr($value, $mbcc);
                break;
            }
        }
    }
    if (!empty($value)) {
        $lines[] = $value;
    }
    return join($lines, "\\n\\t");
}

And I called it as follows:

$meeting_notes="The problem occurs when I have multiple lines in the description. If it contains the text for example I will only get in my outlook calendar description. The part after disappears."
ical_split('DESCRIPTION:', $meeting_notes)

Here the detail of attached ics file.

BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Microsoft Corporation//Outlook 11.0 MIMEDIR//EN
CALSCALE:GREGORIAN
METHOD:REQUEST
BEGIN:VEVENT
DTSTART:20150227T163000Z
DTEND:20150227T173000Z
DTSTAMP:20150211T094306Z
ORGANIZER;CN=Charlene Switzer:MAILTO:email_here
UID:40
ATTENDEE;CUTYPE=INDIVIDUAL;ROLE=REQ-PARTICIPANT;PARTSTAT=NEEDS-ACTION;RSVP=TRUE;CN=name_here;X-NUM-GUESTS=0:MAILTO:email_here
DESCRIPTION:The problem occurs when I have multiple lines in the description. If it contains the text for example I will only get in my outlook calendar description. The part after disappears.
LOCATION:asdf asd
SEQUENCE:0
STATUS:CONFIRMED
TRANSP:OPAQUE
SUMMARY:Meeting
PRIORITY:5
CLASS:PUBLIC
BEGIN:VTIMEZONE
TZID:Eastern
END:VTIMEZONE
END:VEVENT
END:VCALENDAR

Answer 1

To expend on Dmitry's explanation, you need to refer to RFC5545 which specifies the iCalendar format

[3.1. Content Lines][1]

The iCalendar object is organized into individual lines of text, called content lines. Content lines are delimited by a line break, which is a CRLF sequence (CR character followed by LF character).

Lines of text SHOULD NOT be longer than 75 octets, excluding the line break. Long content lines SHOULD be split into a multiple line representations using a line "folding" technique. That is, a long line can be split between any two characters by inserting a CRLF immediately followed by a single linear white-space character (i.e., SPACE or HTAB).

So back to your question, like Dmitry's suggest you should add a TAB or a SPACE after your CRLF but also you should make sure your lines aren't longer than 75bytes. [1]: https://www.rfc-editor.org/rfc/rfc5545#section-3.1