I had the same issue, absolutely could not paste into libreoffice text. After reading comments here, it seemed to me the same as others related, I could copy & paste from within libreoffice, but copy from another application would not overwrite the (apparently separate) libreoffice clipboard. On a hunch, I selected a single blank space from within Libreoffice, and pasted it into my document. That seemed to empty the clipboard and then I was able to copy and paste from the other application. It has worked normally since (so far),
As I am typing this, I notice to the right it says, “This topic has been solved>” Well, excuse me, I seem to have missed that. Something about an old not clearly related or solved bug and something about corrupt files that appear a horrendous mess to have to fix. Doesn’t sound “solved” to me.
Yours is not an answer, at most a comment.
As it is a new question you should create a new question for it with details of your system and LO version, etc.
BTW From the sound of it probably you have a clipboard manager installed which is locking the clipboard, see Bug 136762 - LibreOffice does not paste after v7
This provides a quick workaround to the problem, which none of the other answers does.
LibO hasn’t a separate clipboard. There is an API interface XTransferable usable when programming (user/custom code) in LibO and working in a similar way, but not at all interacting/interfering with the system’s clipboard.
Strange behaviour in any relation to the usage of the clipboard should still mainly be suspected to be due to a once installed (and probably later incompletely “uninstalled”) clipboard manager. Some other “tools” needing to work near the heart (and the brain?) of the OS may also be culprits. Don’t touch the OS except by its own means.
No clipboard manager ever installed, n/a.
A funny aside, message suggests, “reply to this email to respond”. Return address is “noreply@ask.libreoffice.org” LOL
there are! copypaste issues,
see search for copy paste in ‘bugs’ - click to open
it’s more likely you suffer of one of them than you need to rework your system,
look around, find workarounds?, add clue,
next time first search in web and ‘ask’, this question has plenty dups and - insufficient 
- answers …
Needing to replace a probably corrupted user profile is very different from reworking the system.
When I first time had a (completely different) problem with the user profile I got the hint to try the “trick” from a forum -and it worked.
Corrupted user profiles are great in causing very strange problems, and if millions of users don’t experience an issue another user of the same software on the same OS suffers from, this is strange, in a sense.
There may, of course, also be a bug to that effect, but if not described reproducible, it can hardly be fixed. Software development still seems to be partly hazardous. MS proves this every day.
@Lupp: hi,
it may! be one user in millions … äh? did you count them?
in bugs there are 200+ entries for copy paste, 59+ of them i have listed as ‘relevant’, but i haven’t looked through them all yet,
ask throws out 83 pages! of questions about ‘copy paste’ (but the search in ask is not very good),
keep in mind that every user who finds his way into a forum and reports a bug represents up to 50.000 others - or even more - who have the bug but don’t report it, and behind them again up to 1000 times as many who have the bug but don’t notice it, and behind them maybe twice as many who don’t use copy and paste at all …
‘google index’ for ‘libreoffice calc copy paste’ with / without 'problem: 275k out of 258k !!, and that’s not all ‘no problem’ 
“apollo 11” 1,6mio from 11,7mio, “apollo 13” 875k in 4,1 mio, calc worse than apollo 13!,
if you visit a doctor with a wet nose during a flu epidemic, he won’t start with a colonoscopy but with the most likely …
@newbie-02: I woud like to assure you my esteem.
However, I’m a bit tired of this kind of insisting. You know that I cannot count the mentioned numbers. Simply discount my remark if you want. We will both not be able to change the policy concerning bug- fixes whether the bugs are proven bugs or supposed ones.
Some very conscious users of Calc I know from forums seem not to suffer from this supposed bug.
Some very conscious users of LibtreOffice experienced issues due to corrupted user profiles.
Some of them suggested to try a user-profile reset, and some got an ACK+ for it.
In a few cases also Lupp hinted this kind of corruption as the possible background of strange behaviour of LibO, and in some of these cases, the questioner tried, and a profile-reset solved the issue.
Therefore I still hope, @Frants will report if he succeeded based on my hint. As long as he didn’t I will regard the question open.
@Lupp: let’s not argue, let’s work together for a good project, you have good experiences with profile resets, i have none, i have experienced that ‘tinkering’ with the profile by ‘non-professionals’ led to rather unwanted effects … you have the impression that some mistakes are due to the ‘special situation of the user’, i have the impression that too often users are kept busy with requests and ‘standard suggestions’ instead of finally eradicating old known bugs, you? - most developers! - expect ‘stable reproducers for unstable bugs’, i suspect - and find again and again - bugs in places where others think they have been fixed …
What? This is an issue with LibreOffice, not the system.
@endolith:
Who can read is definitely ahead
it’s more likely you suffer of one of them than you need to rework your system,
not ‘then’,
IFAIK issue is resolved since ~ 2 years, was a ‘you need to redial if occupied’ problem …
No, the issue is not resolved, and not a system problem, it’s a flaw in LibreOffice.
@endolith
I don’t understand where you see that I stated it’s a system issue ???
AFAIK there are / have been two nested layers of problem:
1.) LO is sensitive to clipboard managers, doesn’t play well when such is active.
measure: switch off, not always easy if it comes with your system / distro and you even don’t know about.
2.) LO had an incompatibility with an insane windows construction which is similar to ‘redial on busy’, LO didn’t know that they have to try again and again, thus didn’t.
measure: there exists a patch which makes LO ‘redialing’, IMHO it’s in master since about 2 years.
With both of above applied clipboard problems vanished for me.
If you still see problems: research at bugs.documentfoundation.org, ‘clipboard’, ‘copy’, ‘paste’, and if you don’t find a solution file a new bug.
Don’t bother, just a waste of time.
It’s a mess of half-knowing people who are overwhelmed with the complexity of their own product, an unpleasant ‘discussion style’ ( Mike Kakanski ), and a stupid ‘stewardship’ of pushing problems around for years instead of doing something about them, but!
1.) Sometimes they improve something, e.g. against the copy/paste problem, and
2.) We do not have anything better.
Good time of the day everyone!
I videotaped the clipboard issue.
Everything is shown with the regional settings of the interface. I did not switch to English, so as not to “frighten off” the situation. The content of the Windows exchange is shown first. Then I paste in the Calc sheet. It can be seen that the content is pasted that does not match the clipboard. I have been seeing this problem for several years since I started using LibreOffice.
Version: 7.5.5.2 (X86_64) / LibreOffice Community
Build ID: ca8fe7424262805f223b9a2334bc7181abbcbf5e
CPU threads: 4; OS: Windows 10.0 Build 19045; UI render: Skia/Vulkan; VCL: win
Locale: ru-RU (ru_RU); UI: ru-RU
Calc: CL threaded
Good time of the day everyone!
I videotaped the clipboard issue.
Everything is shown with the regional settings of the interface. I did not switch to English, so as not to “frighten off” the situation. The content of the Windows exchange is shown first. Then I paste in the Calc sheet. It can be seen that the content is pasted that does not match the clipboard. I have been seeing this problem for several years since I started using LibreOffice.
P.S. I do not use any additional software for the clipboard.
As of 11/26/2022, I have LibreOffice Writer 7.4.2.3 on Windows 10 Pro, and have experienced the intermittent copy and paste issues described many times on at least 3 different machines, including my office machine provided by our IT Department.
I have no idea what the issue is, but found that logging out of Windows and back in often fixes it temporarily.
Reboot is not needed in my experience.
Hopefully this is helpful to some.
I had this problem, LO not picking up text from the Windows clipboard. Having read some of the replies here, I found the following worked. Go to another application and copy some plain text (e.g. from Notepad, which only deals in plain text). Go to the LO document and hit Ctrl-V – magically it’s back to working as expected. Now go copy the formatted text you really wanted and paste that in – even more magically, that works too.
I’ve no idea how it got into the errored state, but this seems to get you out of it.