It is displayed then your account is restricted by Telegram platform. Contact Spambot or Telegram Support for details. Please note that sometimes Spambot tells "No restrictions", but they are: wait for few hours and ask him again.
It is displayed when Plus Messenger can't connect to Telegram Servers. Read details here.
If you are trying to send text or voice message there is probably connection issue: read details here.
- App cache can be overfilled. Read details here.
- Telegram platform probably temporarily restricts your account for sending video. Try to send video few hours later. You can check this cause by sending video from official app: if it is not sent there too then it is Telegram platform who restricts you; if it is sent there then you should clean Plus Messenger cache.