i usually only see that when the op-1 is out of room
I have the same problem and my OP-1 has 109 mb left. I am trying it with the samples from the ‘Battle 24’ topic.
The amount of MBs remaining is misleading, since the memory reserved for custom patches is more limited than the OP-1’s total storage reading. Because of this, it’s still possible to copy more MBs worth of patches onto the OP-1 than it will allow you to use, once it restarts. Especially since sample based files are much larger than the synth engine patches, a lack of space is probably the reason. Try removing a few old patches and see if the new ones will load.
The maximum number of patches is hardcoded, it does not depend on the amount of free space. Deleting some old patches as suggested by @THSC should fix the issue (unless it is caused by a bad name or corrupted file).