Hi Robin,
The word evil in that verse is translated from the Hebrew word 'ra.'
Strong's H7451 ra‛ - bad or (as noun) evil (naturally or morally). This includes the second (feminine) form; as adjective or noun: - adversity, affliction, bad, calamity, + displease (-ure), distress, evil ([-favouredness], man, thing), + exceedingly, X great, grief (-vous), harm, heavy, hurt (-ful), ill (favoured), + mark, mischief, (-vous), misery, naught (-ty), noisome, + not please, sad (-ly), sore, sorrow, trouble, vex, wicked (-ly, -ness, one), worse (-st) wretchedness, wrong. [Including feminine ra’ah; as adjective or noun.]
Concordant
Ecc 1:13 I applied my heart to inquiring and exploring by wisdom concerning all that is done under the heavens: it is an experience of evil Elohim has given to the sons of humanity to humble them by it.
Rotherham
Ecc 1:13 And I gave my heart to seek and to search out, wisely, concerning all things which are done under the heavens,—the same, is the vexatious employment God hath given to the sons of men, to work toilsomely therein,
LITV
Ecc 1:13 And I gave my heart to seek and to investigate by wisdom concerning all which is done under the heavens. It is an evil task God has given to the sons of men, to be afflicted by it.
RSV
Ecc 1:13 And I applied my mind to seek and to search out by wisdom all that is done under heaven; it is an unhappy business that God has given to the sons of men to be busy with.
NIV
Ecc 1:13 I devoted myself to study and to explore by wisdom all that is done under heaven. What a heavy burden God has laid on men!
GNB
Ecc 1:13 I determined that I would examine and study all the things that are done in this world. God has laid a miserable fate upon us.
NASB
Ecc 1:13 And I set my mind to seek and explore by wisdom concerning all that has been done under heaven. It is a grievous task which God has given to the sons of men to be afflicted with.
KJV
Ecc 1:13 And I gave my heart to seek and search out by wisdom concerning all things that are done under heaven: this sore travail hath God given to the sons of man to be exercised therewith.
Any way you look at this it means something really bad.
mercy, peace and love
Kat